Related Experiment Videos
Left ventricular geometric patterns and QT dispersion in untreated essential hypertension
1Department of Cardiology, Istanbul Faculty of Medicine, University of Istanbul, Türkiye.
Insights
Essential hypertension leads to increased left ventricular mass and QT dispersion. Common adaptations include eccentric hypertrophy and concentric remodeling, with varying impacts on cardiac function and pressure overload.
Area of Science:
- Cardiology
- Hypertension Research
- Cardiac Electrophysiology
Background:
- Essential hypertension is a major risk factor for cardiovascular disease.
- Left ventricular adaptation patterns and their electrophysiological consequences are not fully understood.
- QT dispersion is a marker of repolarization heterogeneity and a predictor of arrhythmias.
Purpose of the Study:
- To investigate left ventricular adaptation patterns in untreated essential hypertension.
- To analyze the relationship between different hypertrophy patterns and QT dispersion.
- To determine the association between geometric patterns and hemodynamic parameters.
Main Methods:
- 107 patients with untreated essential hypertension and 30 controls underwent ECG and echocardiography.
- Left ventricular mass (LVM), relative wall thickness (RWT), and QT dispersion were measured.
- Patients were categorized into normal left ventricle, concentric hypertrophy, eccentric hypertrophy, and concentric remodeling.
Main Results:
- Hypertensive patients showed significantly higher LVM, body mass index, total peripheral resistance (TPR), RWT, and QT dispersion.
- Prevalent patterns were normal left ventricle (41.1%), concentric hypertrophy (10.3%), eccentric hypertrophy (14.95%), and concentric remodeling (32.7%).
- Increased cardiac index was observed in concentric and eccentric hypertrophy; increased TPR in concentric hypertrophy and remodeling. QT dispersion was elevated in hypertensives but similar across hypertrophy types.
Conclusions:
- Eccentric hypertrophy and concentric remodeling are common left ventricular adaptations to essential hypertension.
- Concentric hypertrophy is linked to volume and pressure overload, eccentric hypertrophy to volume overload, and remodeling to pressure overload.
- Different left ventricular geometric patterns appear to have similar effects on QT dispersion.
Abstract:
The spectrum of left ventricular adaptation to hypertension, different types of hypertrophy patterns, and QT dispersion in different types of hypertrophy was investigated in 107 patients with untreated essential hypertension and 30 age- and gender-matched normal adults studied by 12-derivation electrocardiogram (ECG), two-dimensional, and M-mode echocardiography. Left ventricular mass (LVM), body mass index, total peripheral resistance (TPR), relative wall thickness (RWT), and QT dispersion were found to be statistically significantly higher in the hypertension group (P < .001 for all). Among hypertensive patients, 41.1% had both normal LVM and RWT, here called normal left ventricle in hypertension; 10.3% had concentric hypertrophy with increased LVM and RWT; 14.95% had eccentric hypertrophy with increased LVM and normal RWT; and 32.7% had concentric remodeling with normal LVM and increased RWT. Echocardiographically derived cardiac index was higher in the concentric hypertrophy and eccentric hypertrophy patterns (P = .002 and P < .0001, respectively), whereas TPR was higher in the concentric hypertrophy and concentric remodeling patterns (P = .017 and .02, respectively). QT dispersion values were found to be increased in the hypertensive group (P = .001), whereas similar values were calculated for different types of hypertrophy patterns. We conclude that the more common types of ventricular adaptation to essential hypertension are eccentric hypertrophy and concentric remodeling. Concentric hypertrophy is found to be associated with both volume and pressure overload, whereas eccentric hypertrophy is associated with volume overload only and concentric remodeling is associated with pressure overload. But different left ventricular geometric patterns seem to have similar effects on QT dispersion.