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Relation between ECG strain pattern and left ventricular morphology, left ventricular function, and DPTI/SPTI ratio
L Badano1, P Rubartelli, L Giunta
1Servizio di Cardiologia, Ospedale di Nervi, Genoa, Italy.
Insights
Left ventricular structural changes, including larger volumes and mass, are linked to repolarization abnormalities in aortic regurgitation. These changes, not myocardial oxygen supply-demand imbalance, predict ECG repolarization patterns.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Biomedical Engineering
Background:
- Aortic regurgitation (AR) can lead to significant left ventricular (LV) remodeling.
- Electrocardiographic (ECG) repolarization abnormalities are common in AR but their determinants are not fully elucidated.
- Understanding these determinants is crucial for managing AR patients.
Purpose of the Study:
- To assess the relationship between LV structural changes, dysfunction, and subendocardial ischemia with ECG repolarization abnormalities in chronic pure AR.
- To identify key factors contributing to repolarization abnormalities in the absence of coronary artery disease.
Main Methods:
- Studied 53 patients with chronic pure AR and no coronary artery disease.
- Divided patients into groups with abnormal (n=36) and normal (n=17) ECG repolarization patterns.
- Utilized echocardiography and ECG to evaluate LV structure, function, and repolarization characteristics.
Main Results:
- Patients with repolarization abnormalities had significantly larger LV end-diastolic and end-systolic volumes, higher end-diastolic pressure, lower ejection fraction, and greater LV mass.
- Increased peak meridian and circumferential LV stress, along with a more spherical LV shape, were observed in patients with repolarization abnormalities.
- Older age was also associated with repolarization abnormalities, but the myocardial oxygen supply-to-demand ratio was similar between groups.
Conclusions:
- Left ventricular structural remodeling, including increased volumes, mass, and altered shape, are primary determinants of ECG repolarization abnormalities in chronic pure AR.
- Subendocardial ischemia, as estimated by the pressure-time indices, does not appear to be the main driver of these ECG changes in this patient cohort.
- These findings highlight the importance of assessing LV structural and functional status in patients with AR to understand ECG repolarization patterns.
Abstract:
The relative contributions of left ventricular structural changes, dysfunction, and subendocardial ischemia in determining electrocardiographic repolarization abnormalities were assessed in 53 patients with chronic, pure aortic regurgitation and no evidence of coronary artery disease. Thirty-six patients with an abnormal electrocardiographic pattern of repolarization showed larger end-diastolic (154 +/- 46 vs 120 +/- 32 mL/m2; P < .001) and end-systolic (80 +/- 40 vs 52 +/- 30 mL/m2; P = .016) volumes, higher end-diastolic pressure (22 +/- 11 vs 15 +/- 10 mmHg; P = .021), lower ejection fraction (52 +/- 12 vs 59 +/- 13%; P < .05) and greater mass (168 +/- 48 vs 140 +/- 44 g/m2; P < .05) of the left ventricle compared to 17 patients with normal repolarization. Furthermore, patients with repolarization abnormalities also showed higher peak meridian (217 +/- 68 vs 153 +/- 92 Kdyne/cm2; P < .001) and circumferential (358 +/- 110 vs 259 +/- 153 Kdyne/cm2; P < .001) stress and a more spherical shape (end-diastolic shape: 1.4 +/- 0.1 vs 1.5 +/- 0.2, P = .046; end-systolic shape: 1.7 +/- 0.3 vs 1.9 +/- 0.3, P = .026) of the left ventricle. Patients with secondary repolarization abnormalities were also older than patients with normal repolarization (56 +/- 10 vs 40 +/- 11 years; P < .001). However, the diastolic pressure-time index/systolic pressure-time index, which is an estimate of the myocardial oxygen supply-to-demand ratio, was similar in both groups of patients (0.74 +/- 0.3 vs 0.8 +/- 0.2; P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)