541:
794:
interval had been evaluated by having an individual human reader measure approximately nine cardiac beats per clinical timepoint. However, a substantial portion of drug approvals after 2010 have incorporated a partially automated approach, blending automated software algorithms with expert human readers reviewing a portion of the cardiac beats, to enable the assessment of significantly more beats in order to improve precision and reduce cost. In 2014, an industrywide consortium consisting of the FDA,
817:
rheumatoid arthritis. Patients with the highest QTc interval (> 424 ms) had higher mortality than those with a lower QTc interval. The association was lost when calculations were adjusted for C-reactive protein levels. The researchers proposed that inflammation prolonged the QTc interval and created arrhythmias that were associated with higher mortality rates. However, the mechanism by which C-reactive protein is associated with the QTc interval is still not understood.
175:
187:
merges gradually with the baseline. QT interval in an ECG complex can be measured manually by different methods, such as the threshold method, in which the end of the T wave is determined by the point at which the component of the T wave merges with the isoelectric baseline, or the tangent method, in which the end of the T wave is determined by the intersection of a tangent line extrapolated from the T wave at the point of maximum downslope to the isoelectric baseline.
594:
29:
203:- as heart rate increase the QT interval shortens. These changes make it harder to compare QT intervals measured at different heart rates. To account for this, and thereby improve the reliability of QT measurement, the QT interval can be corrected for heart rate (QTc) using a variety of mathematical formulae, a process often performed automatically by modern ECG recorders.
825:
Compared to the general population, type 1 diabetes may increase the risk of mortality, due largely to an increased risk of cardiovascular disease. Almost half of patients with type 1 diabetes have a prolonged QTc interval (> 440 ms). Diabetes with a prolonged QTc interval was associated
186:
II for evaluation of serial ECGs, with leads I and V5 being comparable alternatives to lead II. Leads III, aVL and V1 are generally avoided for measurement of QT interval. The accurate measurement of the QT interval is subjective because the end of the T wave is not always clearly defined and usually
190:
With the increased availability of digital ECGs with simultaneous 12-channel recording, QT measurement may also be done by the 'superimposed median beat' method. In the superimposed median beat method, a median ECG complex is constructed for each of the 12 leads. The 12 median beats are superimposed
834:
QT interval dispersion (QTd) is the maximum QT interval minus the minimum QT interval, and is linked with ventricular repolarization. A QTd over 80 ms is considered abnormally prolonged. Increased QTd is associated with mortality in type 2 diabetes. QTd is a better predictor of cardiovascular
569:
QTc ≤ 0.42 s, QT would be expected to be 0.42 s or less at a heart rate of 60 bpm. For a heart rate of 70 bpm, QT would roughly be expected to be equal to or below 0.40 s. Likewise, for 80 bpm, QT would roughly be expected to be equal to or below 0.38 s.
816:
Rheumatoid arthritis is the most common inflammatory arthritis. Studies have linked rheumatoid arthritis with increased death from cardiovascular disease. In a 2014 study, Panoulas et al. found a 50 ms increase in QTc interval increased the odds of all-cause mortality by 2.17 in patients with
793:
Since 2005, the FDA and
European regulators have required that nearly all new molecular entities be evaluated in a Thorough QT (TQT) or similar study to determine a drug's effect on the QT interval. The TQT study serves to assess the potential arrhythmia liability of a drug. Traditionally, the QT
807:
Electrocardiography is a safe and noninvasive tool that can be used to identify those with a higher risk of mortality. In the general population, there has been no consistent evidence that prolonged QTc interval in isolation is associated with an increase in mortality from cardiovascular disease.
798:
and other organizations released the results of a seminal study indicating how waivers from TQT studies can be obtained by the assessment of early phase data. As the pharmaceutical industry has gained experience in performing TQT studies, it has also become evident that traditional QT correction
315:
In some popular forms of this formula, it is assumed that QT is measured in milliseconds and that RR is measured in seconds, often derived from the heart rate (HR) as 60/HR. Therefore, the result will be given in seconds per square root of milliseconds. However, reporting QTc using this formula
568:
If there is not a very high or low heart rate, the upper limits of QT can roughly be estimated by taking QT = QTc at a heart rate of 60 beats per minute (bpm), and subtracting 0.02 s from QT for every 10 bpm increase in heart rate. For example, taking normal
2082:
319:
In either form, Bazett's non-linear QT correction formula is generally not considered accurate, as it over-corrects at high heart rates and under-corrects at low heart rates. Bazett's correction formula is one of the most suitable QT correction formulae for neonates.
2180:
Montanez A, Ruskin JN, Hebert PR, Lamas GA, Hennekens CH (May 2004). "Prolonged QTc interval and risks of total and cardiovascular mortality and sudden death in the general population: a review and qualitative overview of the prospective cohort studies".
1004:
Salvi V, Karnad DR, Panicker GK, Natekar M, Hingorani P, Kerkar V, et al. (2011). "Comparison of 5 methods of QT interval measurements on electrocardiograms from a thorough QT/QTc study: effect on assay sensitivity and categorical outliers".
1817:
225:
Bazett's formula is based on observations from a study in 1920. Bazett's formula is often given in a form that returns QTc in dimensionally suspect units, square root of seconds. The dimensionally correct form of Bazett's formula is:
883:
Panicker GK, Salvi V, Karnad DR, Chakraborty S, Manohar D, Lokhandwala Y, Kothari S (2014). "Drug-induced QT prolongation when QT interval is measured in each of the 12 ECG leads in men and women in a thorough QT study".
968:
Panicker GK, Karnad DR, Natekar M, Kothari S, Narula D, Lokhandwala Y (2009). "Intra- and interreader variability in QT interval measurement by tangent and threshold methods in a central electrocardiogram laboratory".
560:
Definitions of normal QTc vary from being equal to or less than 0.40 s (≤ 400 ms), 0.41 s (≤ 410 ms), 0.42 s (≤ 420 ms) or 0.44 s (≤ 440 ms). For risk of
508:
191:
on each other and the QT interval is measured either from the earliest onset of the Q wave to the latest offset of the T wave or from the point of maximum convergence for the Q wave onset to the T wave offset.
299:
409:
585:, which are known to degenerate into ventricular fibrillation, associated with higher mortality rates. There are many causes of prolonged QT intervals, acquired causes being more common than genetic.
835:
death than QTc, which was unassociated with mortality in type 2 diabetes. QTd higher than 80 ms had a relative risk of 1.26 of dying from cardiovascular disease compared to a normal QTd.
581:. Higher rates of prolonged QTc are seen in females, older patients, high systolic blood pressure or heart rate, and short stature. Prolonged QTc is also associated with ECG findings called
826:
with a 29% mortality over 10 years in comparison to 19% with a normal QTc interval. Anti-hypertensive drugs increased the QTc interval, but were not an independent predictor of mortality.
1512:
Rossing P, Breum L, Major-Pedersen A, Sato A, Winding H, Pietersen A, et al. (March 2001). "Prolonged QTc interval predicts mortality in patients with Type 1 diabetes mellitus".
1604:
Arking DE, Pfeufer A, Post W, Kao WH, Newton-Cheh C, Ikeda M, et al. (June 2006). "A common genetic variant in the NOS1 regulator NOS1AP modulates cardiac repolarization".
565:, "borderline QTc" in males is 431–450 ms; and, in females, 451–470 ms. An "abnormal" QTc in males is a QTc above 450 ms; and, in females, above 470 ms.
577:
Prolonged QTc causes premature action potentials during the late phases of depolarization. This increases the risk of developing ventricular arrhythmias, including fatal
1841:
Briasoulis A, Agarwal V, Pierce WJ (2011). "QT prolongation and torsade de pointes induced by fluoroquinolones: infrequent side effects from commonly used medications".
548:, Fridericia's formula, and subtracting 0.02 s from QT for every 10 bpm increase in heart rate. Up to 0.42 s (≤ 420 ms) is chosen as normal QTc of QT
1305:
Sagie A, Larson MG, Goldberg RJ, Bengtson JR, Levy D (September 1992). "An improved method for adjusting the QT interval for heart rate (the
Framingham Heart Study)".
1261:
Vandenberk B, Vandael E, Robyns T, Vandenberghe J, Garweg C, Foulon V, Ector J, Willems R (2016-06-17), "Which QT Correction
Formulae to Use for QT Monitoring?",
795:
219:
751:, involve intentional pharmacological QT prolongation. In addition, high blood alcohol concentrations prolong the QT interval. A possible interaction between
1733:
1915:"WAKIX prolongs the QT interval; avoid use of WAKIX in patients with known QT prolongation or in combination with other drugs known to prolong QT interval."
2104:
2435:
2042:
2349:"Increased QT interval dispersion predicts 15-year cardiovascular mortality in type 2 diabetic subjects: the population-based Casale Monferrato Study"
537:
suggests that
Fridericia's method and the Framingham method may produce results most useful for stratifying the 30-day and 1-year risks of mortality.
126:
start to contract to when they finish relaxing. An abnormally long or abnormally short QT interval is associated with an increased risk of developing
2303:"Assessment of QT interval and QT dispersion for prediction of all-cause and cardiovascular mortality in American Indians: The Strong Heart Study"
1464:"Prolonged QTc interval predicts all-cause mortality in patients with rheumatoid arthritis: an association driven by high inflammatory burden"
1696:
429:
312:
to the onset of the next QRS complex. This dimensionally correct formula returns the QTc in the same units as QT, generally milliseconds.
232:
337:
2658:
1104:
Molnar J, Weiss JS, Rosenthal JE (March 1995). "The missing second: what is the correct unit for the Bazett corrected QT interval?".
2930:
1885:
2428:
2024:
808:
However, several studies have examined prolonged QT interval as a predictor of mortality for diseased subsets of the population.
1235:
Fridericia LS (1920). "The duration of systole in the electrocardiogram of normal subjects and of patients with heart disease".
752:
1144:"Update on the evaluation of a new drug for effects on cardiac repolarization in humans: issues in early drug development"
2083:"iCardiac Applies Automated Approach to Thorough QT Study for a Leading Pharmaceutical Company – Applied Clinical Trials"
3027:
2421:
2398:
799:
formulas such as QTcF, QTcB, and QTcLC may not always be suitable for evaluation of drugs impacting autonomic tone.
2043:"E14 Clinical Evaluation of QT/QTc Interval Prolongation and Proarrhythmic Potential for Non-Antiarrhythmic Drugs"
597:
Distribution of QT intervals amongst healthy males and females, and amongst those with congenital long QT syndrome
1697:"Information for Healthcare Professionals: Haloperidol (marketed as Haldol, Haldol Decanoate and Haldol Lactate)"
3032:
1058:
Roguin A (March 2011). "Henry
Cuthbert Bazett (1885-1950)--the man behind the QT interval correction formula".
42:
2057:
183:
2571:
1462:
Panoulas VF, Toms TE, Douglas KM, Sandoo A, Metsios GS, Stavropoulos-Kalinoglou A, Kitas GD (January 2014).
2948:
2703:
2681:
2053:
1701:
1191:
Stramba-Badiale M, Karnad DR, Goulene KM, Panicker GK, Dagradi F, Spazzolini C, et al. (August 2018).
864:
633:
1401:
778:. Acute hypocalcemia causes prolongation of the QT interval, which may lead to ventricular dysrhythmias.
2943:
2688:
2769:
621:
620:
syndrome of
Jervell and Lange-Nielsen is characterized by a prolonged QTc interval in conjunction with
1818:"Guidance on patients at risk of drug-induced sudden cardiac death from off-label COVID-19 treatments"
2973:
2920:
2796:
2776:
2740:
2663:
2623:
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2152:
1346:
2791:
2781:
2671:
578:
62:
2978:
2910:
2855:
2756:
2676:
2560:
2538:
2262:"The effect of proteinuria on relative mortality in type 1 (insulin-dependent) diabetes mellitus"
859:
328:
2556:
2915:
2905:
2819:
2565:
2523:
2518:
1706:
420:
2219:
Solomon DH, Karlson EW, Rimm EB, Cannuscio CC, Mandl LA, Manson JE, et al. (March 2003).
2764:
2408:
639:
2513:
2496:
562:
2413:
423:, which used long-term cohort data of over 5,000 subjects, is considered a better method.
316:
creates a "requirement regarding the units in which the original QT and RR are measured."
308:
is the QT interval corrected for heart rate, and RR is the interval from the onset of one
8:
2860:
2698:
2693:
2528:
2501:
2347:
Giunti S, Gruden G, Fornengo P, Barutta F, Amione C, Ghezzo G, et al. (March 2012).
2119:
617:
582:
534:
107:
33:
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2833:
2586:
2373:
2348:
2237:
2220:
2000:
1975:
1956:
1866:
1788:
1763:
1673:
1648:
1629:
1581:
1556:
1537:
1283:
1244:
1168:
1143:
1083:
1018:
982:
945:
920:
919:
Panicker GK, Karnad DR, Joshi R, Shetty S, Vyas N, Kothari S, Narula D (January 2009).
897:
684:
540:
1117:
2604:
2576:
2378:
2324:
2283:
2242:
2221:"Cardiovascular morbidity and mortality in women diagnosed with rheumatoid arthritis"
2198:
2127:
2098:
2005:
1948:
1858:
1793:
1678:
1621:
1586:
1572:
1529:
1525:
1485:
1322:
1318:
1288:
1214:
1193:"For neonatal ECG screening there is no reason to relinquish old Bazett's correction"
1173:
1159:
1121:
1075:
1071:
1022:
986:
950:
936:
901:
854:
844:
775:
606:
159:
123:
52:
1960:
1870:
1633:
1541:
1087:
2953:
2548:
2403:
2368:
2360:
2314:
2273:
2232:
2190:
1995:
1987:
1938:
1850:
1783:
1779:
1775:
1668:
1660:
1613:
1576:
1568:
1521:
1475:
1427:
1314:
1278:
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1240:
1204:
1163:
1155:
1113:
1067:
1014:
978:
940:
932:
893:
849:
602:
139:
127:
1480:
1463:
743:, have this effect. The mechanism of action of certain antiarrhythmic drugs, like
82:
2803:
2533:
1991:
711:
331:
had proposed an alternative correction formula (QTcF) using the cube-root of RR.
68:
1664:
1428:"Image for Cardiovascular Physiology Concepts > Electrocardiogram (EKG, ECG)"
2963:
2888:
2880:
2474:
2461:
2194:
1209:
1192:
767:
667:
178:
Illustrations of the tangent and threshold methods of measuring the QT interval
163:
131:
1943:
1926:
3021:
2581:
2491:
2484:
2469:
2131:
1441:
1043:
Bazett HC (1920). "An analysis of the time-relations of electrocardiograms".
782:
2319:
2302:
1274:
2995:
2985:
2958:
2847:
2838:
2635:
2609:
2382:
2328:
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2202:
2009:
1952:
1862:
1797:
1682:
1625:
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1533:
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1218:
1177:
1079:
1026:
990:
954:
905:
662:
657:
216:
2287:
1326:
1125:
174:
92:
3000:
2990:
2713:
2708:
2619:
728:
689:
652:
544:
Upper limit of normal QT interval, corrected for heart rate according to
309:
155:
151:
115:
76:
1442:"QTc Prolongation and Risk of Sudden Cardiac Death: Is the Debate Over?"
921:"Z-score for benchmarking reader competence in a central ECG laboratory"
2938:
2723:
2613:
2596:
2479:
2278:
2261:
744:
740:
733:
672:
419:
The
Framingham correction, also called as Sagie's formula based on the
200:
147:
2364:
2301:
Okin PM, Devereux RB, Howard BV, Fabsitz RR, Lee ET, Welty TK (2000).
2153:"CSRC White Paper: QT/QTc Evaluation for Drugs with Autonomic Effects"
1854:
1375:
222:(1885–1950), calculating the heart rate-corrected QT interval (QTcB).
2870:
2641:
2508:
2120:"Norwest-Backed iCardiac to Expand Its Market Thanks to Breakthrough"
723:
706:
1190:
503:{\displaystyle QTlc=1000\left({\frac {QT}{1000}}+0.154(1-RR)\right)}
2898:
2629:
1617:
1260:
756:
135:
1734:"Which psychotropics carry the greatest risk of QTc prolongation?"
593:
294:{\displaystyle QTc_{B}={QT \over {\sqrt {RR \over 1{\text{ s}}}}}}
2893:
1649:"Calculate the QT interval in patients taking drugs for dementia"
771:
748:
694:
404:{\displaystyle QTc_{F}={QT \over {\sqrt{RR \over 1{\text{ s}}}}}}
143:
2409:
Comprehensive QTc
Calculator with 5 formulas at TheCalculator.co
2733:
2728:
613:
119:
2085:. 5 October 2011. Archived from the original on 5 October 2011
1511:
882:
605:, whereas an abnormally shortened QT interval could be due to
28:
2865:
2452:
111:
2259:
1554:
967:
2443:
2346:
2218:
1304:
1142:
Salvi V, Karnad DR, Panicker GK, Kothari S (January 2010).
1974:
Tatonetti NP, Ye PP, Daneshjou R, Altman RB (March 2012).
1973:
1924:
1141:
1003:
2300:
2179:
1976:"Data-driven prediction of drug effects and interactions"
1927:"ECG changes in patients with acute ethanol intoxication"
1646:
1461:
918:
1557:"Drug- and non-drug-associated QT interval prolongation"
110:
used to assess some of the electrical properties of the
2399:
2260:
Borch-Johnsen K, Andersen PK, Deckert T (August 1985).
1925:
Aasebø W, Erikssen J, Jonsbu J, Stavem K (April 2007).
1840:
1731:
1647:
Leitch A, McGinness P, Wallbridge D (September 2007).
114:. It is calculated as the time from the start of the
1732:
Washington NB, Brahm NC, Kissack J (1 October 2012).
1555:
van Noord C, Eijgelsheim M, Stricker BH (July 2010).
432:
340:
235:
1912:
1603:
1406:
Loyola
University Chicago Stritch School of Medicine
1103:
612:
The QTc length is associated with variations in the
601:
An abnormally prolonged QT interval could be due to
211:
The most commonly used QT correction formula is the
134:. Abnormalities in the QT interval can be caused by
2214:
2212:
1761:
150:, by disturbances in the concentrations of certain
122:, and approximates to the time taken from when the
1230:
1228:
502:
403:
293:
1137:
1135:
762:
638:Prolongation of the QT interval may be due to an
3019:
2209:
2103:: CS1 maint: bot: original URL status unknown (
627:
36:showing QT interval calculated by tangent method
1347:"Lesson III. Characteristics of the Normal ECG"
1225:
788:
739:Some second-generation antihistamines, such as
1132:
802:
759:diuretics is associated with QT prolongation.
2429:
2342:
2340:
2338:
1507:
1505:
1503:
1501:
1499:
1457:
1455:
1369:
1367:
1038:
1036:
961:
182:The QT interval is most commonly measured in
1918:
1762:Lewis R, Bagnall AM, Leitner M (July 2005).
1597:
1256:
1254:
1099:
1097:
528:
194:
1768:The Cochrane Database of Systematic Reviews
1640:
1448:. 3 February 2006 – via medscape.com.
1340:
1338:
1336:
199:The QT interval changes in response to the
2436:
2422:
2335:
1496:
1452:
1364:
1298:
1234:
1033:
27:
2372:
2318:
2277:
2236:
1999:
1967:
1942:
1787:
1672:
1580:
1479:
1373:
1282:
1263:Journal of the American Heart Association
1251:
1208:
1167:
1094:
944:
912:
1561:British Journal of Clinical Pharmacology
1333:
774:gland, can cause QT prolongation at the
648:(especially first generation/"typical")
592:
539:
173:
16:Measurement made on an electrocardiogram
2445:Physiology of the cardiovascular system
2150:
1184:
925:Annals of Noninvasive Electrocardiology
876:
811:
753:selective serotonin reuptake inhibitors
323:
3020:
2022:
1815:
1057:
1042:
781:A shortened QT can be associated with
2417:
1811:
1809:
1807:
1727:
1725:
1723:
1351:University of Utah School of Medicine
1060:Pacing and Clinical Electrophysiology
997:
770:, a condition of low function of the
572:
1425:
1344:
1931:Scandinavian Cardiovascular Journal
1883:
206:
13:
2238:10.1161/01.cir.0000054612.26458.b2
2117:
1804:
1720:
1307:The American Journal of Cardiology
1245:10.1111/j.0954-6820.1920.tb18266.x
1106:The American Journal of Cardiology
1019:10.1016/j.jelectrocard.2010.11.010
983:10.1016/j.jelectrocard.2009.01.003
898:10.1016/j.jelectrocard.2013.11.004
829:
820:
414:
14:
3044:
2404:Corrected QT interval calculation
2392:
588:
142:, by certain medications such as
1573:10.1111/j.1365-2125.2010.03660.x
1526:10.1046/j.1464-5491.2001.00446.x
1399:
1160:10.1111/j.1476-5381.2009.00427.x
1072:10.1111/j.1540-8159.2010.02973.x
937:10.1111/j.1542-474X.2008.00269.x
2294:
2253:
2173:
2144:
2111:
2075:
2035:
2016:
1906:
1877:
1834:
1755:
1689:
1548:
1434:
1419:
1393:
1148:British Journal of Pharmacology
2056:. October 2005. Archived from
1980:Science Translational Medicine
1780:10.1002/14651858.CD001715.pub2
1764:"Sertindole for schizophrenia"
1051:
763:Due to pathological conditions
492:
477:
169:
1:
2572:Aortic valve area calculation
2183:Archives of Internal Medicine
1886:"Cardiotoxicity of methadone"
1118:10.1016/S0002-9149(99)80603-1
870:
679:DMARDs and antimalarial drugs
628:Due to adverse drug reactions
2054:Food and Drug Administration
1992:10.1126/scitranslmed.3003377
1702:Food and Drug Administration
1376:"A normal adult 12-lead ECG"
1319:10.1016/0002-9149(92)90562-D
1007:Journal of Electrocardiology
971:Journal of Electrocardiology
886:Journal of Electrocardiology
865:Drug-induced QT prolongation
789:Use in drug approval studies
634:Drug-induced QT prolongation
106:is a measurement made on an
7:
2689:Effective refractory period
2568:) / End-diastolic dimension
2151:Garnett C (29 April 2009).
1816:Malloy T (March 25, 2020).
1665:10.1136/bmj.39020.710602.47
1481:10.1093/rheumatology/ket338
838:
803:As a predictor of mortality
10:
3049:
2195:10.1001/archinte.164.9.943
631:
622:sensorineural hearing loss
3028:Cardiac electrophysiology
2974:Tubuloglomerular feedback
2929:
2921:Critical closing pressure
2879:
2846:
2832:
2812:
2749:
2741:Hexaxial reference system
2664:Cardiac electrophysiology
2651:
2595:
2547:
2460:
2451:
1944:10.1080/14017430601091698
529:Comparison of corrections
195:Correction for heart rate
154:within the blood such as
89:
75:
61:
51:
41:
26:
21:
2949:Renin–angiotensin system
1822:Mayo Clinic News Network
1237:Acta Medica Scandinavica
1210:10.1093/eurheartj/ehy284
579:ventricular fibrillation
525:is measured in seconds.
521:are in milliseconds and
2979:Cerebral autoregulation
2944:Kinin–kallikrein system
2911:Jugular venous pressure
2561:End-diastolic dimension
2539:Pressure volume diagram
2320:10.1161/01.cir.101.1.61
1275:10.1161/JAHA.116.003264
860:QT interval variability
2916:Portal venous pressure
2906:Mean arterial pressure
2820:Ventricular remodeling
2566:End-systolic dimension
2524:Cardiac function curve
2023:Skugor M (June 2019).
1893:Director of Cardiology
1197:European Heart Journal
598:
557:
504:
421:Framingham Heart Study
405:
295:
179:
128:abnormal heart rhythms
3033:Diagnostic cardiology
2557:Fractional shortening
2050:Guidance for Industry
1374:Jenkins D, Gerred S.
796:iCardiac Technologies
640:adverse drug reaction
596:
543:
505:
406:
296:
220:Henry Cuthbert Bazett
177:
2497:End-diastolic volume
2029:The Cleveland Clinic
812:Rheumatoid arthritis
563:sudden cardiac death
430:
338:
324:Fridericia's formula
233:
132:sudden cardiac death
2861:Vascular resistance
2699:Electrocardiography
2694:Pacemaker potential
2624:Conduction velocity
2529:Venous return curve
2502:End-systolic volume
2160:THEW Annual Meeting
2124:Wall Street Journal
2118:Or A (2014-12-16).
618:autosomal recessive
583:Torsades de Pointes
535:retrospective study
160:hormonal imbalances
138:conditions such as
2969:Myogenic mechanism
2587:Left atrial volume
2519:Frank–Starling law
2279:10.1007/bf00281993
1738:Current Psychiatry
685:hydroxychloroquine
599:
573:Abnormal intervals
558:
500:
401:
291:
180:
124:cardiac ventricles
118:to the end of the
3015:
3014:
3011:
3010:
2828:
2827:
2668:Action potential
2659:Conduction system
2605:Cardiac pacemaker
2577:Ejection fraction
2365:10.2337/dc11-1397
1913:https://wakix.com
1855:10.1159/000334441
1514:Diabetic Medicine
1203:(31): 2888–2895.
855:Short QT syndrome
845:Electrocardiogram
776:electrocardiogram
607:short QT syndrome
469:
399:
397:
391:
388:
289:
287:
286:
283:
108:electrocardiogram
100:
99:
34:Electrocardiogram
3040:
2954:Vasoconstrictors
2931:Regulation of BP
2844:
2843:
2777:pulmonary artery
2750:Chamber pressure
2458:
2457:
2438:
2431:
2424:
2415:
2414:
2387:
2386:
2376:
2344:
2333:
2332:
2322:
2298:
2292:
2291:
2281:
2257:
2251:
2250:
2240:
2231:(9): 1303–1307.
2216:
2207:
2206:
2177:
2171:
2170:
2168:
2166:
2157:
2148:
2142:
2141:
2139:
2138:
2115:
2109:
2108:
2102:
2094:
2092:
2090:
2079:
2073:
2072:
2070:
2068:
2063:on March 6, 2010
2062:
2047:
2039:
2033:
2032:
2020:
2014:
2013:
2003:
1986:(125): 125ra31.
1971:
1965:
1964:
1946:
1922:
1916:
1910:
1904:
1903:
1901:
1899:
1890:
1881:
1875:
1874:
1838:
1832:
1831:
1829:
1828:
1813:
1802:
1801:
1791:
1759:
1753:
1752:
1750:
1749:
1729:
1718:
1717:
1715:
1714:
1705:. Archived from
1693:
1687:
1686:
1676:
1644:
1638:
1637:
1601:
1595:
1594:
1584:
1552:
1546:
1545:
1509:
1494:
1493:
1483:
1459:
1450:
1449:
1438:
1432:
1431:
1423:
1417:
1416:
1414:
1412:
1397:
1391:
1390:
1388:
1386:
1371:
1362:
1361:
1359:
1357:
1342:
1331:
1330:
1302:
1296:
1295:
1286:
1258:
1249:
1248:
1232:
1223:
1222:
1212:
1188:
1182:
1181:
1171:
1139:
1130:
1129:
1101:
1092:
1091:
1055:
1049:
1048:
1040:
1031:
1030:
1001:
995:
994:
965:
959:
958:
948:
916:
910:
909:
880:
850:Long QT syndrome
712:fluoroquinolones
603:long QT syndrome
556:in this diagram.
546:Bazett's formula
509:
507:
506:
501:
499:
495:
470:
465:
457:
410:
408:
407:
402:
400:
398:
396:
390:
389:
386:
380:
372:
371:
369:
361:
356:
355:
300:
298:
297:
292:
290:
288:
285:
284:
281:
275:
267:
266:
264:
256:
251:
250:
213:Bazett's formula
207:Bazett's formula
140:long QT syndrome
93:edit on Wikidata
85:
71:
31:
19:
18:
3048:
3047:
3043:
3042:
3041:
3039:
3038:
3037:
3018:
3017:
3016:
3007:
2925:
2875:
2837:
2834:Vascular system
2824:
2808:
2745:
2647:
2632:(Contractility)
2591:
2543:
2534:Wiggers diagram
2447:
2442:
2395:
2390:
2345:
2336:
2299:
2295:
2258:
2254:
2217:
2210:
2178:
2174:
2164:
2162:
2155:
2149:
2145:
2136:
2134:
2116:
2112:
2096:
2095:
2088:
2086:
2081:
2080:
2076:
2066:
2064:
2060:
2045:
2041:
2040:
2036:
2025:"Hypercalcemia"
2021:
2017:
1972:
1968:
1923:
1919:
1911:
1907:
1897:
1895:
1888:
1882:
1878:
1839:
1835:
1826:
1824:
1814:
1805:
1774:(3): CD001715.
1760:
1756:
1747:
1745:
1730:
1721:
1712:
1710:
1695:
1694:
1690:
1645:
1641:
1606:Nature Genetics
1602:
1598:
1553:
1549:
1510:
1497:
1460:
1453:
1440:
1439:
1435:
1424:
1420:
1410:
1408:
1398:
1394:
1384:
1382:
1372:
1365:
1355:
1353:
1343:
1334:
1303:
1299:
1259:
1252:
1239:(53): 469–486.
1233:
1226:
1189:
1185:
1140:
1133:
1102:
1095:
1056:
1052:
1041:
1034:
1002:
998:
966:
962:
917:
913:
881:
877:
873:
841:
832:
830:Type 2 diabetes
823:
821:Type 1 diabetes
814:
805:
791:
765:
636:
630:
591:
575:
555:
551:
531:
458:
456:
455:
451:
431:
428:
427:
417:
415:Sagie's formula
392:
385:
381:
373:
370:
362:
360:
351:
347:
339:
336:
335:
326:
307:
280:
276:
268:
265:
257:
255:
246:
242:
234:
231:
230:
209:
197:
172:
96:
81:
67:
37:
17:
12:
11:
5:
3046:
3036:
3035:
3030:
3013:
3012:
3009:
3008:
3006:
3005:
3004:
3003:
2998:
2993:
2983:
2982:
2981:
2976:
2971:
2964:Autoregulation
2961:
2956:
2951:
2946:
2941:
2935:
2933:
2927:
2926:
2924:
2923:
2918:
2913:
2908:
2903:
2902:
2901:
2896:
2889:Pulse pressure
2885:
2883:
2881:Blood pressure
2877:
2876:
2874:
2873:
2868:
2863:
2858:
2852:
2850:
2841:
2830:
2829:
2826:
2825:
2823:
2822:
2816:
2814:
2810:
2809:
2807:
2806:
2801:
2800:
2799:
2794:
2786:
2785:
2784:
2774:
2773:
2772:
2767:
2759:
2757:Central venous
2753:
2751:
2747:
2746:
2744:
2743:
2738:
2737:
2736:
2731:
2726:
2721:
2716:
2711:
2706:
2696:
2691:
2686:
2685:
2684:
2679:
2674:
2666:
2661:
2655:
2653:
2649:
2648:
2646:
2645:
2639:
2638:(Excitability)
2633:
2627:
2617:
2607:
2601:
2599:
2593:
2592:
2590:
2589:
2584:
2579:
2574:
2569:
2563:
2553:
2551:
2545:
2544:
2542:
2541:
2536:
2531:
2526:
2521:
2516:
2511:
2506:
2505:
2504:
2499:
2489:
2488:
2487:
2482:
2475:Cardiac output
2472:
2466:
2464:
2462:Cardiac output
2455:
2449:
2448:
2441:
2440:
2433:
2426:
2418:
2412:
2411:
2406:
2401:
2394:
2393:External links
2391:
2389:
2388:
2359:(3): 581–583.
2334:
2293:
2272:(8): 590–596.
2252:
2208:
2189:(9): 943–948.
2172:
2143:
2110:
2074:
2034:
2015:
1966:
1917:
1905:
1876:
1849:(2): 103–110.
1833:
1803:
1754:
1719:
1688:
1639:
1618:10.1038/ng1790
1612:(6): 644–651.
1596:
1547:
1520:(3): 199–205.
1495:
1474:(1): 131–137.
1451:
1433:
1418:
1392:
1380:ecglibrary.com
1363:
1332:
1313:(7): 797–801.
1297:
1250:
1224:
1183:
1131:
1112:(7): 537–538.
1093:
1066:(3): 384–388.
1050:
1032:
996:
977:(4): 348–352.
960:
911:
892:(2): 155–157.
874:
872:
869:
868:
867:
862:
857:
852:
847:
840:
837:
831:
828:
822:
819:
813:
810:
804:
801:
790:
787:
768:Hypothyroidism
764:
761:
737:
736:
731:
726:
715:
714:
709:
698:
697:
692:
687:
676:
675:
670:
668:chlorpromazine
665:
660:
655:
646:Antipsychotics
632:Main article:
629:
626:
590:
589:Genetic causes
587:
574:
571:
553:
549:
530:
527:
511:
510:
498:
494:
491:
488:
485:
482:
479:
476:
473:
468:
464:
461:
454:
450:
447:
444:
441:
438:
435:
416:
413:
412:
411:
395:
384:
379:
376:
368:
365:
359:
354:
350:
346:
343:
325:
322:
305:
302:
301:
279:
274:
271:
263:
260:
254:
249:
245:
241:
238:
215:, named after
208:
205:
196:
193:
171:
168:
164:hypothyroidism
98:
97:
90:
87:
86:
79:
73:
72:
65:
59:
58:
55:
49:
48:
45:
39:
38:
32:
24:
23:
15:
9:
6:
4:
3:
2:
3045:
3034:
3031:
3029:
3026:
3025:
3023:
3002:
2999:
2997:
2994:
2992:
2989:
2988:
2987:
2984:
2980:
2977:
2975:
2972:
2970:
2967:
2966:
2965:
2962:
2960:
2957:
2955:
2952:
2950:
2947:
2945:
2942:
2940:
2937:
2936:
2934:
2932:
2928:
2922:
2919:
2917:
2914:
2912:
2909:
2907:
2904:
2900:
2897:
2895:
2892:
2891:
2890:
2887:
2886:
2884:
2882:
2878:
2872:
2869:
2867:
2864:
2862:
2859:
2857:
2854:
2853:
2851:
2849:
2845:
2842:
2840:
2835:
2831:
2821:
2818:
2817:
2815:
2811:
2805:
2802:
2798:
2795:
2793:
2790:
2789:
2787:
2783:
2780:
2779:
2778:
2775:
2771:
2768:
2766:
2763:
2762:
2760:
2758:
2755:
2754:
2752:
2748:
2742:
2739:
2735:
2732:
2730:
2727:
2725:
2722:
2720:
2717:
2715:
2712:
2710:
2707:
2705:
2702:
2701:
2700:
2697:
2695:
2692:
2690:
2687:
2683:
2680:
2678:
2675:
2673:
2670:
2669:
2667:
2665:
2662:
2660:
2657:
2656:
2654:
2650:
2643:
2640:
2637:
2634:
2631:
2628:
2625:
2621:
2618:
2615:
2611:
2608:
2606:
2603:
2602:
2600:
2598:
2594:
2588:
2585:
2583:
2582:Cardiac index
2580:
2578:
2575:
2573:
2570:
2567:
2564:
2562:
2558:
2555:
2554:
2552:
2550:
2546:
2540:
2537:
2535:
2532:
2530:
2527:
2525:
2522:
2520:
2517:
2515:
2512:
2510:
2507:
2503:
2500:
2498:
2495:
2494:
2493:
2492:Stroke volume
2490:
2486:
2485:Stroke volume
2483:
2481:
2478:
2477:
2476:
2473:
2471:
2470:Cardiac cycle
2468:
2467:
2465:
2463:
2459:
2456:
2454:
2450:
2446:
2439:
2434:
2432:
2427:
2425:
2420:
2419:
2416:
2410:
2407:
2405:
2402:
2400:
2397:
2396:
2384:
2380:
2375:
2370:
2366:
2362:
2358:
2354:
2353:Diabetes Care
2350:
2343:
2341:
2339:
2330:
2326:
2321:
2316:
2312:
2308:
2304:
2297:
2289:
2285:
2280:
2275:
2271:
2267:
2263:
2256:
2248:
2244:
2239:
2234:
2230:
2226:
2222:
2215:
2213:
2204:
2200:
2196:
2192:
2188:
2184:
2176:
2161:
2154:
2147:
2133:
2129:
2125:
2121:
2114:
2106:
2100:
2084:
2078:
2059:
2055:
2051:
2044:
2038:
2030:
2026:
2019:
2011:
2007:
2002:
1997:
1993:
1989:
1985:
1981:
1977:
1970:
1962:
1958:
1954:
1950:
1945:
1940:
1936:
1932:
1928:
1921:
1914:
1909:
1894:
1887:
1880:
1872:
1868:
1864:
1860:
1856:
1852:
1848:
1844:
1837:
1823:
1819:
1812:
1810:
1808:
1799:
1795:
1790:
1785:
1781:
1777:
1773:
1769:
1765:
1758:
1743:
1739:
1735:
1728:
1726:
1724:
1709:on 2007-10-11
1708:
1704:
1703:
1698:
1692:
1684:
1680:
1675:
1670:
1666:
1662:
1659:(7619): 557.
1658:
1654:
1650:
1643:
1635:
1631:
1627:
1623:
1619:
1615:
1611:
1607:
1600:
1592:
1588:
1583:
1578:
1574:
1570:
1566:
1562:
1558:
1551:
1543:
1539:
1535:
1531:
1527:
1523:
1519:
1515:
1508:
1506:
1504:
1502:
1500:
1491:
1487:
1482:
1477:
1473:
1469:
1465:
1458:
1456:
1447:
1443:
1437:
1429:
1426:Klabunde RE.
1422:
1407:
1403:
1396:
1381:
1377:
1370:
1368:
1352:
1348:
1345:Yanowitz FG.
1341:
1339:
1337:
1328:
1324:
1320:
1316:
1312:
1308:
1301:
1294:
1290:
1285:
1280:
1276:
1272:
1268:
1264:
1257:
1255:
1246:
1242:
1238:
1231:
1229:
1220:
1216:
1211:
1206:
1202:
1198:
1194:
1187:
1179:
1175:
1170:
1165:
1161:
1157:
1153:
1149:
1145:
1138:
1136:
1127:
1123:
1119:
1115:
1111:
1107:
1100:
1098:
1089:
1085:
1081:
1077:
1073:
1069:
1065:
1061:
1054:
1047:(7): 353–370.
1046:
1039:
1037:
1028:
1024:
1020:
1016:
1013:(2): 96–104.
1012:
1008:
1000:
992:
988:
984:
980:
976:
972:
964:
956:
952:
947:
942:
938:
934:
930:
926:
922:
915:
907:
903:
899:
895:
891:
887:
879:
875:
866:
863:
861:
858:
856:
853:
851:
848:
846:
843:
842:
836:
827:
818:
809:
800:
797:
786:
784:
783:hypercalcemia
779:
777:
773:
769:
760:
758:
754:
750:
746:
742:
735:
732:
730:
727:
725:
722:
721:
720:
719:
713:
710:
708:
705:
704:
703:
702:
696:
693:
691:
688:
686:
683:
682:
681:
680:
674:
671:
669:
666:
664:
661:
659:
656:
654:
651:
650:
649:
647:
643:
641:
635:
625:
623:
619:
615:
610:
608:
604:
595:
586:
584:
580:
570:
566:
564:
547:
542:
538:
536:
526:
524:
520:
516:
496:
489:
486:
483:
480:
474:
471:
466:
462:
459:
452:
448:
445:
442:
439:
436:
433:
426:
425:
424:
422:
393:
382:
377:
374:
366:
363:
357:
352:
348:
344:
341:
334:
333:
332:
330:
321:
317:
313:
311:
277:
272:
269:
261:
258:
252:
247:
243:
239:
236:
229:
228:
227:
223:
221:
218:
214:
204:
202:
192:
188:
185:
176:
167:
165:
161:
157:
153:
149:
145:
141:
137:
133:
129:
125:
121:
117:
113:
109:
105:
94:
88:
84:
80:
78:
74:
70:
66:
64:
60:
56:
54:
50:
46:
44:
40:
35:
30:
25:
20:
2996:Carotid body
2959:Vasodilators
2839:hemodynamics
2718:
2644:(Relaxation)
2636:Bathmotropic
2610:Chronotropic
2356:
2352:
2313:(1): 61–66.
2310:
2306:
2296:
2269:
2266:Diabetologia
2265:
2255:
2228:
2224:
2186:
2182:
2175:
2163:. Retrieved
2159:
2146:
2135:. Retrieved
2123:
2113:
2087:. Retrieved
2077:
2065:. Retrieved
2058:the original
2049:
2037:
2028:
2018:
1983:
1979:
1969:
1937:(2): 79–84.
1934:
1930:
1920:
1908:
1896:. Retrieved
1892:
1879:
1846:
1842:
1836:
1825:. Retrieved
1821:
1771:
1767:
1757:
1746:. Retrieved
1741:
1737:
1711:. Retrieved
1707:the original
1700:
1691:
1656:
1652:
1642:
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1564:
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1471:
1468:Rheumatology
1467:
1445:
1436:
1421:
1409:. Retrieved
1405:
1402:"Medicine I"
1395:
1383:. Retrieved
1379:
1354:. Retrieved
1350:
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1236:
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1196:
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999:
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970:
963:
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806:
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738:
717:
716:
700:
699:
678:
677:
663:mesoridazine
658:thioridazine
645:
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576:
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559:
545:
532:
522:
518:
514:
513:Again, here
512:
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327:
318:
314:
303:
224:
217:physiologist
212:
210:
198:
189:
181:
156:hypokalaemia
103:
101:
3001:Glomus cell
2991:Aortic body
2986:Paraganglia
2797:ventricular
2770:ventricular
2719:QT interval
2714:QRS complex
2709:PR interval
2682:ventricular
2620:Dromotropic
2307:Circulation
2225:Circulation
2067:December 9,
1898:21 February
1884:Haigney M.
1744:(10): 36–39
729:vemurafenib
718:Other drugs
701:Antibiotics
690:chloroquine
653:haloperidol
310:QRS complex
170:Measurement
104:QT interval
77:MedlinePlus
22:QT interval
3022:Categories
2939:Baroreflex
2856:Compliance
2848:Blood flow
2724:ST segment
2652:Conduction
2642:Lusitropic
2614:Heart rate
2597:Heart rate
2549:Ultrasound
2480:Heart rate
2137:2021-01-26
1843:Cardiology
1827:2020-05-19
1748:2020-05-19
1713:2007-09-18
1385:28 January
871:References
745:amiodarone
741:astemizole
734:pitolisant
707:macrolides
673:sertindole
616:gene. The
329:Fridericia
201:heart rate
148:pitolisant
43:ICD-10-PCS
2899:Diastolic
2871:Perfusion
2630:Inotropic
2509:Afterload
2132:0099-9660
724:methadone
484:−
304:where QTc
2894:Systolic
2672:cardiac
2383:22301117
2329:10618305
2247:12628952
2203:15136301
2099:cite web
2089:19 March
2010:22422992
1961:11828588
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1798:16034864
1683:17855324
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1626:16648850
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1219:29860404
1178:19775279
1088:43739886
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1027:21238976
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757:thiazide
162:such as
158:, or by
53:ICD-9-CM
2514:Preload
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2288:4054448
2052:. U.S.
2001:3382018
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1674:1976518
1582:2909803
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1126:7864010
946:6932360
772:thyroid
749:sotalol
695:quinine
387: s
282: s
144:sotalol
136:genetic
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2804:Aortic
2792:atrial
2765:atrial
2761:Right
2734:U wave
2729:T wave
2704:P wave
2677:atrial
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2866:Pulse
2813:Other
2788:Left
2782:wedge
2453:Heart
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2061:(PDF)
2046:(PDF)
1957:S2CID
1889:(PDF)
1867:S2CID
1630:S2CID
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475:0.154
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112:heart
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2379:PMID
2325:PMID
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2243:PMID
2199:PMID
2167:2014
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2069:2009
2006:PMID
1949:PMID
1900:2013
1859:PMID
1794:PMID
1772:2005
1679:PMID
1622:PMID
1587:PMID
1530:PMID
1486:PMID
1413:2010
1387:2018
1358:2010
1323:PMID
1289:PMID
1215:PMID
1174:PMID
1122:PMID
1076:PMID
1023:PMID
987:PMID
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