Relation Between Left Ventricular Geometry and Transmural Dispersion of Repolarization

doi:10.1016/j.amjcard.2005.05.053

The American Journal of Cardiology

Volume 96, Issue 7, 1 October 2005, Pages 952-955

https://doi.org/10.1016/j.amjcard.2005.05.053 Get rights and content

Studies have shown an association between left ventricular (LV) geometry and complex ventricular ectopic activity. Increased transmural dispersion of repolarization (TDR), which correlates to the interval from the peak to the end of the T wave (Tpe) on the surface electrocardiogram, is linked to ventricular tachyarrhythmias. The relation between LV geometry and TDR is unknown. The mean Tpe interval, measured from leads V₁ to V₃ of the surface electrocardiogram, was assessed in 300 patients (50% men) who had normal LV systolic function and QRS duration and were categorized into 3 equal groups, which were matched by age and gender, according to echocardiographically determined LV geometry (normal structure, concentric remodeling, and LV hypertrophy). The Tpe interval was corrected for the QT interval using Tpe/QTc and was compared among the 3 groups. Compared with those who had normal LV structure, the Tpe interval was significantly prolonged in those who had LV hypertrophy and significantly shortened in those who had concentric remodeling (p = <0.0001 for the 2 comparisons). Correcting for the QT interval using Tpe/QTc yielded similar results. Thus, TDR was increased in patients who had LV hypertrophy but decreased in concentric remodeling compared with those who had normal cardiac structure. Although LV hypertrophy represents a maladaptive geometric process that results in an unfavorable electrical substrate, concentric remodeling may represent a structural adaptation that has a more favorable electrical milieu.

References (18)

M. Zabel et al.
Electrocardiographic indexes of dispersion of ventricular repolarizationan isolated heart validation study
J Am Coll Cardiol
(1995)
N. Watanabe et al.
Transmural dispersion of repolarization and ventricular tachyarrhythmias
J Electrocardiol
(2004)
R.B. Devereux et al.
Echocardiographic assessment of left ventricular hypertrophycomparison to necropsy findings
Am J Cardiol
(1986)
W.H. Gaasch
Left ventricular radius to wall thickness ratio
Am J Cardiol
(1979)
N. Reichek et al.
Reliable estimation of peak left ventricular systolic pressure by M-mode echographic-determined end-diastolic relative wall thicknessidentification of severe valvular aortic stenosis in adult patients
Am Heart J
(1982)
K. Wachtell et al.
Change of left ventricular geometric pattern after 1 year of antihypertensive treatmentthe Losartan Intervention For Endpoint reduction in hypertension (LIFE) study
Am Heart J
(2002)
L. Oikarinen et al.
Relation of QT interval and QT dispersion to regression of echocardiographic and electrocardiographic left ventricular hypertrophy in hypertensive patients. The Losartan Intervention for Endpoint Reduction (LIFE) study
Am Heart J
(2003)
S. Sicouri et al.
A subpopulation of cells with unique electrophysiological properties in the deep subepicardium of the canine ventriclethe M cell
Circ Res
(1991)
G.X. Yan et al.
Cellular basis for the normal T wave and the electrocardiographic manifestations of the long-QT syndrome
Circulation
(1998)

There are more references available in the full text version of this article.

Cited by (17)

Assessment of repolarization heterogeneity for prediction of mortality in cardiovascular disease: Peak to the end of the T wave interval and nondipolar repolarization components
2011, Journal of Electrocardiology
Citation Excerpt :
In a large and well-investigated population of cardiovascular patients, we found TpTe intervals to be shorter in those dying compared with those surviving a mean follow-up of more than 10 years. This is in obvious contrast to previous studies9-21 investigating TpTe intervals in various high-risk populations, that is, patients with hypertrophic cardiomyopathy,9,19 post–myocardial infarction,9,20 long QT syndrome,10,15,21 inducible ventricular tachycardia,13,14,16 end-stage renal disease,11 repaired tetralogy of Fallot,12 or Brugada syndrome.17,18 By finding prolonged TpTe intervals in patients compared with controls, these studies concluded that prolongation of TpTe interval is a marker of increased risk.
In the canine wedge preparation, the interval from the peak to the end of the T wave (TpTe) reflects transwedge heterogeneities. Increase of ventricular dispersion of action potential durations has been repeatedly shown to be arrhythmogenic; thus, prolonged TpTe intervals were assumed to reflect increased risk. However, despite attempted extrapolation to clinical electrocardiograms, the appropriateness of this assumption has not been investigated in a large population. In another animal model, nondipolar components of the descending T-wave limb (TWRd) have been shown to correlate with TpTe interval. Although total T-wave nondipolar components (TWRt), believed to reflect heterogeneities during total repolarization, were shown associated with worse outcome of cardiac patients, this has not been investigated for TWRd.
Male cardiovascular patients (n = 813) had digital 12-lead electrocardiograms recorded between 1984 and 1991 and were followed until 2000. Using commercial and previously validated technology, QT intervals, TpTe intervals, TWRd, and TWRt were calculated, heart rate corrected, and compared between survivors and nonsurvivors. Their predictive power was also compared with established markers of mortality risk. In contrast to former reports, TpTe_c intervals were significantly shorter in nonsurvivors (98.76 ± 20.63 milliseconds vs 103.14 ± 20.87 milliseconds, P = .016) and not predictive of outcome. Although TWRd_c was significantly higher in nonsurvivors (0.007% ± 0.02% vs 0.005% ± 0.08%, P = .03), it was also not predictive of outcome. Only increased TWRt_c, increased heart rate, and increased age were predictive of death.
The findings challenge the concept that prolongation of TpTe corresponds to higher risk of death from any cause in every population. Further investigations are needed to confirm that clinically measured TpTe reflects transmural repolarization heterogeneity in all clinical populations and indeed is a useful risk marker.
Alterations in QT interval in patients undergoing living donor liver transplantation
2011, Transplantation Proceedings
Citation Excerpt :
Despite marked QTc prolongation, this study showed that there was no incidence of severe ventricular dysrrhythmias, except infrequent premature ventricular complexes. We speculated that prolonged QTc might be compensated with a reciprocal decline of the Tp–e, which is a relevant arrhythmic risk factor, reflecting total dispersion of repolarization.15–17 However, it is difficult to explain the mechanisms of these reciprocal changes in QTc parameters; therefore, further studies are needed to clarify these findings.
QT interval prolongation, predisposing to ventricular tachyarrhythmia, has frequently been observed in patients with liver cirrhosis. During liver transplantation (LT) surgery, electrolyte imbalance and hemodynamic instability may affect QT interval changes. We evaluated the alterations in QT parameters at each stage of LT surgery.
We assessed 50 living donor LT recipients without overt heart disease for the corrected QT (QTc) and the interval from peak to the end of the T wave (T_p–e) automatically using Bazett's formula with LabChart software. QT parameters, laboratory and hemodynamic data were simultaneously collected in the following stages of LT: before anesthetic induction (baseline), pre-anhepatic, anhepatic, 1 hour postreperfusion, and after hepatic artery anastomosis. Recipients were allocated into 2 groups according to their baseline QTc: ≥440 versus <440 msec.
QTc progressively rose from the pre-anhepatic stage remaining prolonged in each stage of LT surgery compared with the baseline. In the anhepatic stage, 54% of recipients showed marked prolongation of QTc ≥500 msec (522 ± 14), which indicated the potential for a fatal ventricular dysrhythmia: 77% and 36% in groups with QTc ≥440 and <440 msec, respectively. As opposed to changes in QTc, T_p–e in the anhepatic stage decreased significantly; however, it returned to the baseline level in the neohepatic stage.
A prolonged QTc interval (≥500 msec) was frequently observed throughout the procedure of LT, even among patients with baseline QTc <440 msec, emphasizing the importance of optimizing electrolyte balance and hemodynamic status to reduce greater risk of perioperative arrhythmias.
Apical conicity ratio: A new index on left ventricular apical geometry after myocardial infarction
2010, Journal of Thoracic and Cardiovascular Surgery
Citation Excerpt :
There is evidence that left ventricular geometry is an important intermediate phenotype to study of cardiovascular diseases. Precise and intensive evaluations of left ventricular geometry are fundamental.23-25 There are many conventional measurements of left ventricular geometry including SI, vSI, and EI, which can be used to evaluate the global left ventricular shape and have been applied clinically.5-7
Our objective was to introduce a new index to evaluate left ventricular aneurysm by quantitative analysis of left ventricular apical geometry.
A total of 116 selected subjects underwent magnetic resonance imaging, 28 healthy volunteers, 29 patients with dilated cardiomyopathy, and 59 patients with ischemic heart disease (26 with left ventricular aneurysm; 33 with no aneurysm). The apical conicity ratio was calculated as the ratio of left ventricular apical area over apical triangle.
Diastolic apical conicity ratio of patients with left ventricular aneurysm was 1.62 ± 0.20 and systolic apical conicity ratio was 1.78 ± 0.43. After left ventricular reconstruction, the diastolic apical conicity ratio decreased to 1.47 ± 0.23 and the systolic ratio to 1.51 ± 0.21, which came close to the normal level, whereas other global indices remained. In patients with dilated cardiomyopathy, sphericity index and eccentricity index increased significantly without changes in the apical conicity ratio. Among patients with ischemic heart disease, the apical conicity ratio of the group with left ventricular aneurysm was significantly higher than that of the group without an aneurysm when the other indices between the 2 groups showed no statistically difference. Receiver operating characteristic curves showed only apical conicity ratio had high power of discriminating left ventricular aneurysm from no aneurysm.
The new index, apical conicity ratio, can be used to quantify the regional left ventricular deformation, especially in patients with left ventricular aneurysm resulting from myocardial infarction.
Cardiac fatigue in long-distance runners is associated with ventricular repolarization abnormalities
2009, Heart Rhythm
Citation Excerpt :
Although it might be tempting to ascribe at least part of the physiological mechanism behind the observed VR alterations to transient changes in ion-channel function, the background to our observations might be more complex. A relation has been found between the Tpeak-end interval (measured in precordial leads) and left ventricular geometry.27 Furthermore, the right ventricle appears to be especially sensitive to cardiac fatigue,28 and altered intracavitary pressures may conceivably induce the mechanoelectrical changes that need to be considered.29
Prolonged exercise can induce cardiac fatigue, which is characterized by biomarker release and impaired myocardial function. The impact on ventricular electrophysiology is largely unknown.
The objective of this study was to examine changes in ventricular repolarization after a 30-km cross-country race in runners aged ≥55 years.
Fifteen healthy participants (62 ± 5 years) were assessed using biomarkers (N-terminal pro-brain natriuretic peptide [NT-proBNP], troponin T [TnT]), tissue Doppler echocardiography, and vectorcardiography at baseline, within 1 hour postrace and on days 1 and 6 postrace.
During the race, NT-proBNP increased from 42 ng/L (interquartile range 25–117) to 187 ng/L (113–464), and TnT increased from undetectable levels to 0.03 μg/L (0.015–0.05). Global strain (19.1% ± 2.2%) decreased on day 1 (17.2% ± 1.8%) and day 6 (17.9% ± 1.5%; P <.01). QT_c increased from 431 ± 15 ms prerace to 445 ± 22 ms postrace and 445 ± 15 ms on day 1 (P <.05), mainly because of an increased T_peak-end interval (prerace 108 ± 13 ms, postrace 127 ± 43 ms, day 1 127 ± 43 ms; P <.05). Postrace, T_area (baseline 75 ± 26 μVs) peaked on day 1 (105 ± 42 μVs) and remained high on day 6 (89 ± 37 μVs; P <.05). Runners with higher baseline NT-proBNP developed greater impairment of myocardial velocities (rho = −0.68 to −0.54; P <.05) and a larger increase in T_area (rho = 0.73; P <.01).
Cardiac fatigue induced by prolonged exertion is associated with sustained abnormalities in ventricular repolarization. Runners with higher baseline NT-proBNP are especially liable to such alterations of cardiac function.
Comparison of Cardiac and Peripheral Arterial Stiffening and Ventriculovascular Uncoupling in Patients With Uncomplicated Hypertension Versus Patients With Hypertension After Heart Transplantation
2006, American Journal of Cardiology
Citation Excerpt :
As reported by Saba et al6 in hypertensive patients, the increased arterial load in the heart transplant recipients may have led to the observed doubling in the prevalence of concentric remodeling in this population. As we have recently demonstrated, concentric remodeling is the most common LV geometric abnormality in large echocardiographic populations and is associated with increased arterial load, increased circulating catecholamines, reduced coronary flow reserve, and increased cardiac morbidity and mortality.10,20 There are several study limitations.
Despite normal ejection fractions, patients who undergo heart transplantation (HT) have low peak aerobic capacity and reduced arterial compliance, suggesting “ventriculovascular uncoupling.” To what extent this is related to post-transplantation hypertension versus the unique characteristics of the donor-recipient relation remains poorly understood. Echocardiograms were retrospectively reviewed from 126 normal subjects, 309 patients with uncomplicated hypertension (UH), and 58 consecutive patients with HT >1 year after the procedure who were stable without evidence of rejection. Left ventricular (LV) end-systolic elastance (Ees), a measure of LV systolic performance; effective arterial elastance (Ea), a measure of vascular stiffness; and Ea/Ees, a parameter describing ventriculovascular coupling, were obtained. Compared with normal subjects, tandem increases in Ea (+24% and +85%, all p values <0.0001) and Ees (+23% and +33%, all p values <0.0001) were observed in patients with UH and HT, respectively, with patients with HT having significantly higher values than those with UH (both p values <0.05). Although the Ea/Ees ratio remained similar between normal subjects and patients with UH, patients with HT exhibited increases in the Ea/Ees ratio (all p values <0.01) and reduced stroke volume indexes (−20% and −22%, respectively, all p values <0.05). These changes were associated with a doubling of LV concentric remodeling in patients with HT compared with those with UH (67% vs 34%, p <0.0001). In conclusion, HT is associated with increases in Ees, Ea, and the Ea/Ees ratio, suggesting ventriculovascular uncoupling and maximal LV stroke work. These aberrations, which determine cardiovascular performance in the setting of HT, are not simply explained by vascular age or post-transplantation hypertension but may adversely affect functional capacity.
Repolarisation in patients with ischaemic and nonischaemic cardiomyopathy: assessment of parameters of transmural dispersion of repolarisation using the 65-lead surface ECG
2020, Cardiovascular Medicine

View all citing articles on Scopus

View full text

Systemic hypertensionRelation Between Left Ventricular Geometry and Transmural Dispersion of Repolarization

J Am Coll Cardiol

J Electrocardiol

Am J Cardiol

Am J Cardiol

Am Heart J

Am Heart J

Am Heart J

A subpopulation of cells with unique electrophysiological properties in the deep subepicardium of the canine ventriclethe M cell

Circ Res

Cellular basis for the normal T wave and the electrocardiographic manifestations of the long-QT syndrome

Circulation

Systemic hypertension
Relation Between Left Ventricular Geometry and Transmural Dispersion of Repolarization