The left atrium and diastolic dysfunction in hypertensive left ventricular hypertrophy: a consideration of size and function?

Association Between ECG Abnormalities and Mortality in a Low-Risk Population

BACKGROUND

The ECG is a simple, noninvasive screening method for cardiovascular disease and arrhythmia. The impact of ECG abnormality on mortality is not certain in low-risk populations. To address this, we evaluated the association between ECG abnormality and mortality.

METHODS AND RESULTS

We retrospectively assessed baseline ECG and all-cause mortality and cardiovascular mortality in 660 383 patients presenting for medical check-ups. Baseline ECG abnormalities were classified according to the Minnesota Code. Among the total 660 383 participants, 23 609 (3.6%) had major and 110 038 (16.7%) had minor ECG abnormalities. All-cause mortality occurred in 7751 patients (1.1%) and cardiovascular mortality in 1180 (0.18%) over a median follow-up period of 8.8 years. Major ECG abnormalities were associated with all-cause mortality (hazard ratio [HR], 1.11 [95%, 1.03-1.2]) and cardiovascular mortality (HR, 1.92 [95% CI, 1.63-2.27]) compared with no ECG abnormalities. All-cause mortality was associated with right atrial enlargement (HR, 2.11 [95% CI, 1.1-4.07]), left atrial enlargement (HR, 1.76 [95% CI, 1.1-2.84]), sinus tachycardia (HR, 1.52 [95% CI, 1.15-2.01]), complete atrioventricular block (HR, 2.1 [95% CI, 1.05-4.2]), atrial fibrillation (HR, 1.52 [95% CI, 1.26-1.84]), and left ventricular hypertrophy (HR, 1.15 [95% CI, 1.02-1.3]). Cardiovascular mortality was associated with left atrial enlargement (HR, 4.52 [95% CI, 2.15-9.5]), atrial fibrillation (HR, 3.22 [95% CI, 2.33-4.46]), left ventricular hypertrophy (HR, 1.72 [95% CI, 1.35-2.19]), major Q-wave abnormality (HR, 1.6 [95% CI, 1.08-2.39]), and major ST-T abnormality (HR, 1.76 [95% CI, 1.01-3.04]).

CONCLUSIONS

ECG abnormalities, including left atrial enlargement, left ventricular hypertrophy, atrial fibrillation, and major Q-wave and ST-T abnormalities, were associated with cardiovascular mortality in a low-risk population.

Association of left atrial enlargement with left ventricular hypertrophy and diastolic dysfunction: a tissue Doppler study in echocardiographic practice

BACKGROUND

Left atrial (LA) enlargement is a powerful risk factor for cardiovascular diseases; little information is available about its prevalence and correlates in subjects free of overt cardiac disease seen in echocardiographic practice.

AIM

We evaluated the prevalence of LA enlargement (LAE) and the relationship with left ventricular (LV) mass and diastolic function in subjects with preserved LV systolic function referred to an echocardiographic study for routine clinical indications.

METHODS

1104 subjects (mean age 58 ± 16 years, 46% men, 57% hypertensives) underwent a comprehensive echo-Doppler examination. LAE and LV hypertrophy (LVH) were defined as LA volume index (LAVI) >29 ml/m(2) and LV mass index (LVMI) >50 g/h(2.7), respectively. Abnormalities of LV relaxation and LV filling were diagnosed by age-related thresholds of lateral annular velocity (Ei) and by early mitral flow velocity to Ei ratio (E/Ei) ≥16, respectively.

RESULTS

Overall, 10% of echocardiographic examinations fulfilled the criteria for LAE, 46% for LVH, 45% for altered LV relaxation and 5% for altered LV filling index. LVH progressively increased from 25% to 75% across LAVI quartiles. More patients in the highest quartile exhibited abnormal indexes of LV relaxation and LV filling compared with lower quartiles. In multivariate analysis, LV mass index (β = 0.408), age (β = 0.188), E/Ei ratio (β = 0.140) and Ei (β = 0.140) emerged as major correlates of LAE (p at least <0.01 for all).

CONCLUSIONS

LAE is a frequent finding in patients with preserved systolic function seen in current practice; this abnormality is strongly related to LVH and to diastolic dysfunction. Early detection of LAE may identify patients at higher cardiovascular risk and promote appropriate prevention strategies.