Influence of posture and handgrip on the QT interval in left ventricular hypertrophy and in chronic heart failure

1999 ◽  
Vol 96 (4) ◽  
pp. 403-407 ◽  
Author(s):  
Patrick DAVEY
Keyword(s):  
Heart Failure ◽  
Left Ventricular Hypertrophy ◽  
Qt Interval ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Qtc Interval ◽  
Dominant Hand ◽  
Control Subjects ◽  
Qt Intervals ◽  
And Control

In certain disease states prolongation of the QT interval has been shown to be arrhythmogenic. Whether QTc interval changes with position and thus whether certain positions are more arrhythmogenic than others is not known for different diseases that predispose to arrhythmias, and was therefore studied. Patients with left ventricular hypertrophy and heart failure, and the appropriate matched controls, were recruited. Subjects were studied in the lying, sitting, standing and squatting positions and had QT intervals determined by computer algorithm 2 min after each position change. After resting, QT interval was determined while the subjects performed maximum handgrip exercise with their dominant hand. QT intervals were rate-corrected using Bazett's method. QTc interval is prolonged in heart failure patients compared with either left ventricular hypertrophy or control subjects in the lying and sitting position, but not in the standing or squatting position. The QTc intervals for heart failure and control subjects were, respectively, 443±7 ms versus 421±6 ms when lying (P< 0.05), 451±10 ms versus 419±6 ms when sitting (P< 0.05), 429±10 versus 414±7 ms when standing (P not significant) and 437±10 versus 419±8 ms when squatting (P not significant). The values for patients with hypertrophy did not differ from control values. Maximum handgrip does not affect the QTc interval in heart failure, but prolongs it in both the hypertrophy and control groups. Position and static exercise are important modifiers of QTc interval and their effect depends on the condition of the left ventricle.

Prolongation of the QT interval in heart failure occurs at low but not at high heart rates

2000 ◽  
Vol 98 (5) ◽  
pp. 603-610 ◽  
Author(s):  
P. P. DAVEY ◽  
C. BARLOW ◽  
G. HART
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Left Ventricular Hypertrophy ◽  
Qt Interval ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Qt Interval Prolongation ◽  
Qt Intervals ◽  
Ventricular Structure ◽  
And Function

Abnormal left ventricular structure and function as in, for example, left ventricular hypertrophy or chronic heart failure, is associated with sudden cardiac death and, when the ejection fraction is depressed, with prolongation of the QT interval. The dependence on heart rate of QT interval prolongation in these conditions, and the relationship of any abnormalities either to deranged autonomic nervous system function or to an adverse prognosis, has not been well studied. We therefore investigated (1) the dependence on heart rate of the QT interval, and (2) the relationship between both QT interval and the QT/heart rate slope and markers of adverse prognosis in these two conditions. The QT interval was measured at rest and during exercise in 34 subjects with heart failure, 16 subjects with left ventricular hypertrophy and 16 age-matched controls with normal left ventricular structure and function. QTc (corrected QT) intervals at rest were significantly longer in heart failure patients (471±10 ms) than in controls (421±6 ms) or in subjects with hypertrophy (420±6 ms) (P < 0.05). At peak exercise, despite the attainment of similar heart rates, the QT intervals no longer differed from each other, being 281±7 ms for controls, 296±11 ms in hypertrophy and 303±10 ms in heart failure (no significant difference). The QT/heart rate slope was significantly increased in heart failure [2.3±0.1 ms·(beats/min)-1] compared with controls [1.55±0.06 ms·(beats/min)-1] and hypertrophy [1.66±0.1 ms·(beats/min)-1] (P < 0.001). In left ventricular hypertrophy, despite animal data suggesting that QT interval prolongation should occur, no abnormalities were found in QT intervals at rest or during exercise. The QT/heart rate slope did not relate to any markers for an adverse prognosis, except that of prolongation of QT interval. Long QT intervals were associated principally with impairment of left ventricular systolic function. Our data emphasize the dynamic nature of the QT interval abnormalities found in heart failure.

scholarly journals Electrocardiographic Abnormalities and Mortality in Epilepsy Patients

Medicina ◽  
2021 ◽  
Vol 57 (5) ◽  
pp. 504
Author(s):  
Normunds Suna ◽  
Inga Suna ◽  
Evija Gutmane ◽  
Linda Kande ◽  
Guntis Karelis ◽  
...  
Keyword(s):  
Heart Rate ◽  
General Population ◽  
Left Ventricular Hypertrophy ◽  
Qt Interval ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Mortality Data ◽  
Qtc Interval ◽  
Study Objective

Background and Objectives: People with epilepsy (PWE) have a 2–3 times higher mortality rate than the general population. Sudden unexpected death in epilepsy (SUDEP) comprises a significant proportion of premature deaths, whereas sudden cardiac death (SCD) is among the leading causes of sudden death in the general population. Cardiac pathologies are significantly more prevalent in PWE. Whether electrocardiographic (ECG) parameters are associated with remote death in PWE has yet to be elucidated. The study objective was to assess whether interictal ECG parameters are associated with mortality in the long-term. Materials and Methods: The study involved 471 epilepsy patients who were hospitalized after a bilateral tonic-clonic seizure(s). ECG parameters were obtained on the day of hospitalization (heart rate, PQ interval, QRS complex, QT interval, heart rate corrected QT interval (QTc), ST segment and T wave changes), as well as reported ECG abnormalities. Mortality data were obtained from the Latvian National Cause-of-Death database 3–11, mean 7.0 years after hospitalization. The association between the ECG parameters and the long-term clinical outcome were examined. Results: At the time of assessment, 75.4% of patients were alive and 24.6% were deceased. Short QTc interval (odds ratio (OR) 4.780; 95% confidence interval (CI) 1.668–13.698; p = 0.004) was associated with a remote death. After the exclusion of known comorbidities with high mortality rates, short QTc (OR 4.631) and ECG signs of left ventricular hypertrophy (OR 5.009) were associated with a remote death. Conclusions: The association between routine 12-lead rest ECG parameters—short QTc interval and a pattern of left ventricular hypertrophy—and remote death in epilepsy patients was found. To the best of our knowledge, this is the first study to associate rest ECG parameters with remote death in an epileptic population.

QT-interval variability and autonomic control in hypertensive subjects with left ventricular hypertrophy

2002 ◽  
Vol 102 (3) ◽  
pp. 363-371 ◽  
Author(s):  
Gianfranco PICCIRILLO ◽  
Giuseppe GERMANÒ ◽  
Raffaele QUAGLIONE ◽  
Marialuce NOCCO ◽  
Filippo LINTAS ◽  
...  
Keyword(s):  
Sudden Death ◽  
Left Ventricular Hypertrophy ◽  
Qt Interval ◽  
Ventricular Arrhythmias ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Cardiac Repolarization ◽  
Control Subjects ◽  
Qt Variability ◽  
Normotensive Control

Left ventricular hypertrophy is a risk factor for sudden death. Malignant ventricular arrhythmias originate from altered cardiac repolarization. Ample data have described spatial abnormalities in cardiac repolarization [QT interval (QT) dispersion] in subjects with hypertension; more data are needed on temporal changes. This study was designed to assess the QT variability index (QTVI), the slope between QT and the RR interval (QT-RRslope) and spectral QT variability in subjects with arterial hypertension. The results were compared with those from a population at high risk of sudden death, i.e. patients with hypertrophic cardiomyopathy (HCM) who had received an implantable cardioverter/defibrillator (ICD), and those from normotensive control subjects. A total of 44 hypertensive subjects, six patients with HCM and an ICD and 33 control subjects underwent simultaneous short-term recording (256 beats) of QT, RR and systolic blood pressure variability, in the supine position, during controlled breathing. QTVI and spectral components of QT variability in the hypertensive group were significantly higher than in normotensive control subjects (P < 0.001), but significantly lower than in patients with HCM and an ICD (P < 0.001). The severity of left ventricular hypertrophy correlated significantly with QTVI and the ratio of low-frequency (LF) to high-frequency (HF) power obtained from the RR variability spectra (RRLF/HF, slope = 0.24, P < 0.05; QTVI, slope = 4.06, P < 0.0001; intercept, slope = 2.40, P < 0.05; χ2 = 38.8; P < 0.0001). The QT-RR slope was significantly higher only in patients with HCM and an ICD (P < 0.001). In conclusion, the increased QTVI and the correlation of this index with left ventricular hypertrophy indicates that hypertension increases temporal cardiac repolarization abnormalities. At the level of the cardiac sinus node, this alteration is associated with increased sympathetic and reduced vagal modulation. As already noted in patients with HCM, the increased QTVI could be a factor responsible for triggering malignant ventricular arrhythmias in subjects with hypertension.

scholarly journals Association of Cardiac Injury and Malignant Left Ventricular Hypertrophy With Risk of Heart Failure in African Americans

2019 ◽  
Vol 4 (1) ◽  
pp. 51 ◽  
Author(s):  
Ambarish Pandey ◽  
Neil Keshvani ◽  
Colby Ayers ◽  
Adolfo Correa ◽  
Mark H. Drazner ◽  
...  
Keyword(s):  
Heart Failure ◽  
African Americans ◽  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Cardiac Injury ◽  
Left Ventricular

Abstract MP31: Left Ventricular Hypertrophy by Electrocardiogram versus Cardiac Magnetic Resonance Imaging as a Predictor for Heart Failure: The MESA Study

Circulation ◽  
2016 ◽  
Vol 133 (suppl_1) ◽  
Author(s):  
Abdullahi O Oseni ◽  
Waqas T Qureshi ◽  
Mohammed F Almahmoud ◽  
Alain Bertoni ◽  
David A Bluemke ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Heart Failure ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Ventricular Hypertrophy ◽  
Cardiac Magnetic Resonance Imaging ◽  
Ventricular Hypertrophy ◽  
Predictive Ability ◽  
Left Ventricular ◽  
Resonance Imaging

Background: Left ventricular hypertrophy (LVH) is an established risk factor for heart failure (HF). However, it is unknown whether LVH detected by electrocardiogram (ECG-LVH) is equivalent to LVH ascertained by cardiac magnetic resonance imaging (MRI-LVH) in terms of prediction of incident HF using risk prediction models like the Framingham Heart Failure Risk Score (FHFRS). Methods: This analysis included 4745 (mean age 61+10 years, 53.5% women, 61.7% non-whites) from the Multi-Ethnic Study of Atherosclerosis who were free of cardiovascular disease at the time of enrollment. ECG-LVH was defined using Cornell’s criteria while MRI-LVH was derived from left ventricular (LV) mass measured by cardiac MRI. Cox proportional hazard regression was used to examine the association between ECG-LVH and MRI-LVH with incident HF. Harrell’s concordance C-index was used to estimate the predictive ability of the FHFRS when either ECG-LVH or MRI-LVH were included as one of its components. The added predictive ability of ECG-LVH and MRI-LVH were investigated using integrated discrimination improvement (IDI) index and relative IDI. Results: ECG-LVH was present in 291(6.1%) while MRI-LVH was present in 499 (10.5%) of the participants. Over a median follow up of 10.4 years, 140 participants developed HF. Both ECG-LVH [HR (95% CI): 2.25(1.38-3.69)] and MRI-LVH [HR (95% CI): 3.80(1.56-5.63)] were associated with an increased risk of HF in multivariable adjusted models (Table 1). The ability of FHFRS to predict HF was improved with MRI-LVH (C-index 0.871, 95% CI: 0.842-0.899) when compared with ECG-LVH (C-index 0.860, 95% CI: 0.833-0.888) (p < 0.0001). To assess the potential clinical utility of using LVH-MRI instead of ECG-LVH, we calculated several measures of reclassification (Table 1), which were consistent with the statistically significantly improved C-statistic with MRI-LVH. Conclusion: Both ECG-LVH and MRI-LVH are predictive of HF when used in the FHFRS. Substituting MRI-LVH for ECG-LVH improves the predictive ability of the FHFRS.

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