Left Ventricular Hypertrophy (LVH)

 

Left Ventricular Hypertrophy (LVH) is the thickening of the myocardium (muscle) of the left ventricle of the heart. While initially a compensatory mechanism to chronic pressure overload, LVH can become a risk factor for various cardiovascular diseases.

Diagnostic Criteria:

LVH is primarily diagnosed using ECG and echocardiography:

1. ECG Criteria:

   • Sokolow-Lyon Criteria: S wave in V1 + tallest R wave in V5 or V6 ≥ 35 mm.
   • Cornell Voltage Criteria: S wave in V3 + R wave in aVL > 28 mm (men) or > 20 mm (women).
   • RaVL Criteria: R wave amplitude in lead aVL > 11 mm.
   • Others: Numerous other ECG findings may suggest LVH, including aVL ≥ 13 mm, and a sum of the R wave in lead I plus S wave in lead III > 25 mm.

2. Echocardiography:

   • This imaging technique measures the actual thickness of the ventricular walls. LVH is diagnosed when the myocardial wall thickness is greater than 15 mm.

Causes:

The development of LVH is commonly due to conditions that demand increased force from the heart to pump blood:

• Hypertension: Chronic high blood pressure increases the resistance against which the heart must pump, leading to thickening of the myocardium.
• Aortic Stenosis: Narrowing of the aortic valve causes pressure overload in the left ventricle.
• Athletic Training: Intense, prolonged athletic training can lead to “athlete’s heart,” a form of physiological LVH.
• Cardiomyopathies: Certain genetic conditions can cause LVH without hypertension or valvular disease.
• Other Causes: Including but not limited to obesity, age, and race.

Significance and Clinical Implications:

LVH is not a disease but a marker for diseases that affect the heart:

• Risk of Arrhythmias: Thickened myocardium can lead to an altered electrical conduction pathway, increasing the risk of ventricular arrhythmias.
• Impaired Coronary Perfusion: Increased heart muscle mass can outstrip its blood supply, potentially leading to ischemia.
• Diastolic Dysfunction: Thickening of the heart muscle can affect the heart’s ability to relax and fill, leading to heart failure with preserved ejection fraction (HFpEF).
• Sudden Cardiac Death: Especially in athletes, LVH can be a risk factor for sudden cardiac death due to its association with dangerous arrhythmias.
• Prognostic Value: Presence of LVH has been linked with increased mortality in several conditions, including hypertension and heart failure.

Management:

Management focuses on treating the underlying cause of LVH and may include:

• Blood Pressure Control: Through lifestyle changes and medications such as ACE inhibitors, angiotensin II receptor blockers, or beta-blockers.
• Valvular Surgery: Corrective surgery may be indicated in cases like severe aortic stenosis.
• Lifestyle Modifications: Including regular exercise, dietary adjustments, and weight loss.
• Monitoring: Regular follow-up with echocardiography and ECGs to monitor the progression of LVH.