Left ventricular hypertrophy

Electrocardiographic diagnostics (ECG)

Electrocardiography is a crucial primary method for detecting electrical changes that accompany the pathological thickening of the heart muscle. When analyzing the cardiogram of a patient with suspected left ventricular hypertrophy, specialists look for a number of specific markers.

First of all, characteristic signs of ischemic damage or pronounced hemodynamic overload include ST-segment depression, which is particularly clearly visualized in chest leads $V_{4-6}$. In addition, long-standing pathology may lead to severe conduction abnormalities of the electrical impulse. One such manifestation is the development of left bundle branch block.

It is important to note that the pathological process is rarely limited to a single chamber. In the later stages of the disease, signs of biventricular hypertrophy begin to be registered on the cardiogram, i.e., combined thickening of the walls of both ventricles. Signs of left atrial overload during sinus rhythm are also frequently recorded — a widened notched P wave in leads I and II (P-mitrale). As rhythm disturbances progress, atrial fibrillation may develop, accompanied by the disappearance of the P wave.

Echocardiography (EchoCG): morphology and function

EchoCG is a key imaging method that allows not only confirming the presence of hypertrophy but also assessing the severity of structural disorders. Two-dimensional echocardiography records direct thickening of the interventricular septum and the posterior wall of the left ventricle.

Along with an increase in muscle mass, the device registers processes of cardiac remodeling. This manifests as dilatation — a pathological increase in the dimensions of the left ventricular cavity (end-systolic and end-diastolic). In conjunction with this, dilatation of the left atrial cavity is also frequently detected.

Special attention during the study is paid to myocardial contractility. In pronounced changes, a local decrease in contractility is observed: areas of hypokinesia (impaired motion) or areas of dyskinesia (paradoxical wall motion) appear.

Doppler ultrasound is actively used to assess hemodynamics. This method has high sensitivity in detecting reverse blood flow (regurgitation). Color Doppler mapping visualizes blood flow and the regurgitant jet, while quantitative assessment allows calculating the regurgitant orifice area and the volume of returning blood, even if direct signs of valve leaflet defect are not visible.

X-ray imaging

Chest X-ray becomes an informative technique in pronounced hemodynamic disorders. A classic sign of the described pathology on an anteroposterior radiograph is a visible enlargement of the left ventricular shadow.

For differential diagnosis, it is important to evaluate the configuration of the heart shadow as a whole. For example, when a "mitral configuration" forms, the dimensions of the left ventricle usually remain normal, but the "waist" of the heart becomes smoothed out. This occurs due to the protrusion of the arches along the left contour: the left atrial appendage (forming the "third arch") and the pulmonary artery trunk (second arch).

Additionally, X-ray images may reveal signs of systemic pulmonary circulation overload. These include increased vascularization of the upper lung lobes and signs of interstitial fluid transudation. X-rays also allow for the detection of structural calcification (e.g., of the mitral valve).

Relationship with systemic body responses

Left ventricular involvement is closely related to changes in other parts of the cardiovascular system. When signs of pulmonary hypertension join, concomitant right ventricular (RV) hypertrophy develops.

On the ECG, this is reflected as a deviation of the electrical axis of the heart to the right (rightogram formation), the appearance of a tall R wave in leads $V_{1-2}$, and secondary changes in the ST segment and T wave. Two-dimensional EchoCG in such cases visualizes enlargement of the right ventricular cavity and thickening of its walls.

In addition, echocardiography allows the detection of intracardiac thrombi, which are most often mural in nature. Secondary symptoms also include changes in the patient's appearance — the formation of Facies mitralis (youthful appearance combined with a cyanotic flush on the cheeks). A comprehensive assessment of all these data gives the physician a complete picture of the severity of the pathology.

Class and exam questions

What else to study on this topic

• Signs of left atrial overload and P-mitrale formation
• Evaluation of regurgitation using color Doppler mapping
• Development of biventricular hypertrophy in late stages
• Differential diagnosis with the "mitral configuration" of the heart
• Impact of pulmonary hypertension on the right heart chambers

Other topics in the "Cardiovascular system" section

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