Left ventricular hypertrophy

Mechanisms and general electrocardiographic signs

Any thickening of the heart muscle, including left ventricular localization, has characteristic manifestations on the cardiogram. First, the amplitude of the ventricular complex (specifically, the R wave) and the atrial P wave significantly increase. Second, the electrical axis of the heart (EAH) shifts toward the increased muscle mass — that is, it deviates to the left. In addition, indirect signs of myocardial ischemia and various electrical conduction disturbances are frequently recorded on the tracing.

Rhythm disturbances often arise against the background of structural myocardial remodeling. One of the most frequent complications associated with chamber enlargement is atrial fibrillation (flutter/fibrillation). In the late stages of the disease, especially when complicated by pulmonary hypertension, the pathological process can also involve the right heart chambers, leading to biventricular hypertrophy (involvement of both ventricles).

Specific ECG criteria

To make an accurate diagnosis, the physician evaluates the amplitude of the waves primarily in the chest leads.

The main (key) criteria include:

• The height of the R wave in leads V5 or V6 exceeds 16 mm.
• A strict amplitude pattern is observed: RV6 is greater than RV5, which in turn exceeds RV4.
• The depth of the S wave in the right chest leads (V1 and V2) is more than 12 mm.
• The sum of the amplitudes of RV5 (or V6) and SV1 exceeds 28 mm.

Additionally, the terminal portion of the ventricular complex is evaluated. Typical markers include a negative T wave and ST-segment depression in the left leads (V5, V6). Concurrently, a compensatory ST-segment elevation may be recorded in the right leads (V1, V2).

Echocardiography and dopplerography

Echocardiography (EchoCG) is the leading tool for the morphological assessment of the heart. The method clearly visualizes left ventricular wall thickening and reveals dilation (pathological expansion) of its cavity and the left atrium. The ultrasound protocol must necessarily determine the left ventricular mass index (LVMI) and diastolic function parameters.

Dopplerography plays a key role in hemodynamic assessment, possessing high sensitivity for detecting reverse blood flow (regurgitation). Color Doppler mapping visualizes the direction of blood flow and the regurgitation jet itself. Using quantitative assessment (a combination of 2D and pulsed-wave modes), the physician can accurately calculate the volume of returning blood and the area of the regurgitant orifice, although direct signs of a valve leaflet defect may often not be visible.

Radiological presentation

In severe heart defects and significant hemodynamic disturbances, radiological examination demonstrates high informativeness.

Progression of the pathology is indicated by a noticeable increase in left ventricular dimensions on the image. Another characteristic sign is dilation of the left atrium and its appendage. Visually in the anteroposterior projection, this manifests as the formation of the so-called "third arc" along the left contour of the cardiac silhouette.

Dispanserization monitoring rules

Patients with a confirmed diagnosis require regular instrumental monitoring. A standard 12-lead ECG must be recorded at least twice a year. When interpreting the cardiogram, the physician is required to calculate special indices — the Sokolov–Lyon index and the Cornell index.

Cardiac ultrasound is performed upon enrolling the patient in dispensary follow-up, and is subsequently scheduled according to clinical indications. However, EchoCG becomes strictly mandatory at least once a year in two cases:

1. If target blood pressure levels cannot be achieved against the background of prescribed therapy.
2. If calculations based on the ECG reveal signs of progressive thickening of the myocardial walls.

Class and exam questions

What else to study on this topic

• Calculation formulas for the Sokolov–Lyon index and the Cornell parameter
• Diagnosis of right ventricular hypertrophy on ECG
• Signs of left atrial overload (P-mitrale)
• Specific ECG changes in right atrial hypertrophy (P-pulmonale)
• The role of dopplerography in the quantitative assessment of valvular regurgitation

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.