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.

ECG appearances.

Appearances cont..

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).Prolonged P wave duration (>0.12 secs). Pronounced notch with peak to peak >0.04secs.Pronounced notch with peak to peak >0.04secs.

Right Atrial Hypertrophy / Enlargement.

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).

RAH Appearance.

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.

Left Ventricular Hypertrophy Appearance.

LVH Appearance.

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.

Right Ventricular Hypertrophy.

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 Appearance Right Ventricular Hypertrophy.

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.