Atrial and Ventricular Hypertrophy. ECG Features and Common Causes.
Aims and Objectives. • Understand pathophysiology of types of hypertrophy. • Common patient presentation and symptoms. • ECG appearances associated with different types of hypertrophy. • Pitfalls in diagnosis from ECG.
Left Atrial Hypertrophy / Enlargement. Thickening of wall. Dilatation of chamber (enlargement). Increased volume. Increased muscle mass.
Some causes. Mitral and / or aortic valve disease. Left ventricular systolic and diastolic dysfunction. Cardiomyopathy - hypertrophic / dilated. Atrial fibrillation. Left atrial mass. Hypertension.
Common ECG Features of LAH. • Usually seen in late portion of P wave. • Often biphasic in V1 - larger negative deflection. • RA conducts anteriorly (+ initially) • Large LA mass conducts posteriorly (-ive component). • Prolonged P wave duration (>0.12 secs). • Pronounced notch with peak to peak >0.04secs.
Some causes. Tricuspid and / or pulmonary valve disease. Lung disease. Congenital heart disease (ASD, PFO, VSD). RV systolic and diastolic dysfunction. Mitral stenosis (pressure back-up).
Common ECG Appearance. Tall, peaked P wave (>2.5mm). Best seen lead II - often throughout ECG. Known as P pulmonale.
Left Ventricular Hypertrophy. Thickened walls. Dilated chamber. Increased muscle mass or increased volume.
Some causes of LVH. Aortic valve disease. Coarctation of the aorta. Cardiomyopathy - dilated, hypertrophic. Hypertension. Heart Failure - systolic.
Commonly Used Criteria for LVH. Scoring System. Suggested if >5 points. Chou, T. and Knilans, T.K. (1996). Electrocardiography in Clinical Practise. 4th Ed. Philadelphia: Saunders. • ECG Feature: • Amplitude: • Largest R or S wave in limb leads >20mm. • S wave leads V1 and V2 >30mm. • R waves in leads V5 or V6 >30mm. 3 POINTS. ST-T wave changes typical for LVH. 3 POINTS. Left atrial involvement. 3 POINTS. Left axis deviation. 2 POINTS. QRS Duration of >0.09s. 1 POINT.
Some causes of RVH. Pulmonary hypertension (numerous causes - primary and secondary - also cor pulmonale). Mitral stenosis. Pulmonary valve disease. Congenital heart disease (VSD, Ebsteins Anomaly). RV systolic dysfunction (e.g. post inferior MI).
ECG Criteria for RVH. • Right axis deviation of +110 degrees or more. • Dominant R wave in lead V1. • R wave in lead V1 >7mm. • Other supporting criteria: • ST segment depression and T inversion V1 - V4. • Deep S waves V5, V6, I and aVL.
Conclusion. • LAH – ECG appearance and common causes. • RAH – appearance and causes. • LVH – appearance, certainty of diagnosis, causes and pitfalls. • RVH – appearance, causes and pitfalls.