Is hypertensive left ventricular hypertrophy a cause of sustained ventricular arrhythmias in humans?

Area of Science:

• Cardiology
• Electrophysiology
• Hypertension Research

Background:

• Sudden cardiac death (SCD) is primarily caused by sustained ventricular arrhythmias (VAs).
• Left ventricular hypertrophy (LVH) is a common consequence of systemic hypertension.
• The role of hypertensive LVH as an independent risk factor for life-threatening arrhythmias remains unclear.

Purpose of the Study:

• To review the evidence evaluating left ventricular hypertrophy (LVH) secondary to systemic hypertension as an isolated risk factor for ventricular arrhythmogenesis.
• To determine if hypertensive LVH directly contributes to sustained ventricular arrhythmias (VAs) and sudden cardiac death (SCD).

Main Methods:

• Literature review of animal models and clinical data concerning hypertensive LVH and ventricular arrhythmias.
• Analysis of studies examining ion channel function, gap junction distribution, and fibrosis in hypertensive LVH.
• Evaluation of clinical trial data on the progression from non-sustained to sustained VAs and SCD in patients with hypertensive LVH.

Main Results:

• Animal models of hypertensive LVH show structural and electrical remodeling, including ion channel and gap junction alterations, and fibrosis.
• Clinical data indicate an increased prevalence and complexity of non-sustained VAs in patients with hypertensive LVH.
• Limited evidence directly links hypertensive LVH to sustained VAs or SCD, often confounded by co-existing coronary artery disease (CAD) or other factors.

Conclusions:

• Hypertensive LVH is associated with non-sustained ventricular arrhythmias but may not be an independent risk factor for sustained VAs or SCD.
• Pathophysiological changes in hypertensive LVH might be more homogenous than in conditions like hypertrophic cardiomyopathy (HCM) or myocardial infarction.
• Sustained VAs in the context of hypertensive LVH are likely precipitated by other conditions such as CAD or electrolyte disturbances.