Left ventricular hypertrophy, or LVH, is a condition where the muscle of the heart’s main pumping chamber, the left ventricle, becomes thickened. This thickening is a response to factors that overwork the heart muscle, such as high blood pressure or a faulty heart valve. An electrocardiogram (ECG) showing “LVH with secondary repolarization abnormality” indicates that the heart’s electrical pattern has changed as a direct result of this muscle thickening.
Decoding the Diagnosis
Left ventricular hypertrophy develops when the left ventricle must consistently work harder to pump blood. Like any muscle subjected to a heavier workload over time, it grows larger. This physical thickening of the ventricle walls is the “hypertrophy” part of the diagnosis.
The phrase “repolarization abnormality” describes how this thickening affects the heart’s electrical activity, which is recorded by an ECG. After each heartbeat (depolarization), the heart’s muscle cells must electrically reset (repolarization) to prepare for the next beat. The thickened muscle in LVH alters this resetting process, creating a specific pattern on the ECG often called a “strain” pattern.
The word “secondary” signifies the electrical changes are a consequence of the muscle’s increased mass. The abnormality is not due to a primary electrical problem within the heart’s conduction system or a lack of blood flow, known as ischemia. This distinction points medical evaluation toward the underlying physical cause of the thickened heart muscle rather than an intrinsic electrical issue.
Common Underlying Causes
The most frequent cause of left ventricular hypertrophy is chronic high blood pressure (hypertension). This condition forces the left ventricle to generate more force with each beat to circulate blood. Over time, this effort causes the muscular wall of the ventricle to thicken and stiffen.
Another cause is aortic valve stenosis, where the valve controlling blood flow out of the left ventricle becomes narrowed. This obstruction requires the ventricle to pump much harder to push blood through the smaller opening. A leaky aortic or mitral valve (regurgitation) can also lead to LVH over time.
LVH can also be caused by a genetic condition called hypertrophic cardiomyopathy, where gene mutations cause the heart muscle to thicken without an external pressure load. Intense, long-term athletic training can lead to an enlarged heart muscle, but this is a normal adaptation known as “athlete’s heart” and is structurally different from pathological hypertrophy.
Diagnostic Process and Confirmation
An initial finding of LVH with a secondary repolarization abnormality often comes from a routine electrocardiogram (ECG). The ECG measures the heart’s electrical signals, and specific patterns, like increased voltage in certain leads, can suggest the left ventricle muscle is thicker than normal. While the ECG is a useful screening tool, it is not definitive.
To confirm the diagnosis, measure the thickness of the ventricle walls, and assess heart function, doctors order an echocardiogram. This test uses ultrasound waves to create detailed, moving images of the heart and is the standard for diagnosing LVH. It allows clinicians to visualize the heart muscle, check how the chambers and valves are working, and determine the severity of the hypertrophy.
Depending on the findings and the suspected underlying cause, further tests may be recommended. A cardiac MRI can provide even more detailed images of the heart muscle. If hypertension is the suspected cause but blood pressure readings are variable, a 24-hour ambulatory blood pressure monitor may be used to get a more accurate picture of a patient’s daily blood pressure patterns.
Management and Treatment Strategies
Treatment for LVH focuses on managing its underlying cause, not the ECG pattern itself. Addressing the root problem can reduce strain on the heart and may lead to a regression of the muscle thickening. The goal is to lower the workload of the left ventricle to prevent further stiffening and complications like heart failure.
Lifestyle modifications are a component of management, especially for high blood pressure. Recommendations to lower blood pressure and improve heart health include:
- A diet low in sodium
- Regular moderate exercise
- Maintaining a healthy weight
- Limiting alcohol consumption
- Avoiding tobacco products
Alongside lifestyle changes, medications are often prescribed to control blood pressure and reduce cardiac strain. Common classes of drugs include angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs), which relax blood vessels to lower pressure. Beta-blockers may also be used to slow the heart rate and reduce the force of contractions. If a structural issue like aortic stenosis is the cause, a surgical procedure to repair or replace the valve may be necessary.