1 بسم الله الرحمن الرحیم

Atrial and Ventricular Hypertrophy ECG Features and Common Causes ALI BARABADI University of Guilan

Aims and Objectives. Understand pathophysiology of types of hypertrophy. Common patient presentation and symptoms. ECG appearances associated with different types of hypertrophy.

CARDIAC HYPERTROPHY Physiological hypertrophy (Athlete’s Heart) Pathological hypertrophy (Cardiovascular disease) Finding animal study Identified key signaling mechanisms To diagnosis, New Therapeutic  Increased heart mass  Normal or Enhanced cardiac function  Reversible  Increased heart mass  Reduced cardiac function  Irreversible  Cell death and fibrosis  Increased mortality

Pressure overload Systolic wall stress Mechanical transducers Eccentric hypertrophy Volume overload Diastolic wall stress Concentric hypertrophy Responses to hemodynamic overload hypertrophy Extracellular and intracellular signals

7 Signaling pathway in Physiological Cardiac Hypertrophy PI3K (p110α) Akt1Akt1 Angiogenesis Contractility Heart growth Anti-apoptosis Anti-fibrosis Pathological pathway IGF-1 IGF-1Receptor Cell membrane

8 Signaling pathway in Physiological Cardiac Hypertrophy mTOR dependent pathway mTOR independent pathway » Regulation of protein synthesis and cell size Akt1Akt1 mTORmTOR Protein synthesis Protein degradation Cell size

Distinct characteristics of physiological and pathological cardiac hypertrophy PI3K (p110α) Akt1Akt1 New therapeutic strategy activate regulators of PI3K (p110α) pathway, i.e. ‘PI3K–regulated microRNAs’ IGF-1 IGF-1Receptor Cell membrane

Lead I extends from the right to the left arm Lead II extends from the right arm to the left foot Lead III extends from the left arm to the left foot Einthoven’s Triangle

Normal Intervals PR 0.20 sec (less than one large box) QRS 0.08 – 0.10 sec (1-2 small boxes) QT 450 ms in men, 460 ms in women Based on sex / heart rate R-R interval with normal HR

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.

Left Atrial Abnormality II: wide P wave V1: negative P wave is “1 box wide, 1 box deep” wider; left atrial enlargement should prolong the P wave > 0.12 sec. V 1 may show a bi-phasic P wave

Right Atrial Hypertrophy / Enlargement.

Some causes. Tricuspid and / or pulmonary valve disease. Lung disease. Congenital heart disease RV systolic and diastolic dysfunction. Mitral stenosis (pressure back-up).

Right Atrial Abnormality Criteria Tall P waves in lead II Tall, peaked P wave (>2.5mm). Best seen lead II - often throughout ECG. Normal P wave is less than 2.5 mm tall and 0.12 seconds wide. With right atrial hypertrophy, P waves are typically taller than 2.5 mm but not wider than 0.12 sec.

Right Ventricular Hypertrophy.

Some causes of RVH. Pulmonary hypertension Mitral stenosis. Pulmonary valve disease. Congenital heart disease RV systolic dysfunction

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 T inversion V1 - V4. Deep S waves V5, V6, I and aVL.

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. 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. Left axis deviation QRS Duration of >0.09s. If S wave in V 1 + R wave in V 5 or V 6 ≥ 35 mm (≥ 50 for under 35 yrs of age) R wave > 11 mm in aV L R wave > 15 mm in lead I

LVH Types Volume Over LoadPressure Over Load

LVH Types Pressure Over load Like in hypertension, IHD) Ischemic heart disease( LV strain pattern – ST depression with T ↓ in V5, V6, L1 and aVL leads Volume Over load Like in Mitral or Aortic regurgitation Shows prominent positive T waves in V5, V6, L1 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.

Web Site Instruction Berne and Levy Physiology, 6th Edition Bruce M. Koeppen, Bruce A. Stanton R. Klablunde -Cardiovascular Physiology Concepts -Lippincott (2005) Leonard S. Lilly-Pathophysiology of Heart Disease_ A Collaborative Project of Medical Students and Faculty, Fifth Edition-Lippincott Williams & Wilkins (2010) Leonard S. Lilly-Pathophysiology of Heart Disease_ A Collaborative Project of Medical Students and Faculty, Fifth Edition-Lippincott Williams & Wilkins (2010) (Expert consult) Robert O Bonow_ Eugene Braunwald_ et al-Braunwald's heart disease _ a textbook of cardiovascular medicine-Elsevier Saunders (2012) (Expert consult) Robert O Bonow_ Eugene Braunwald_ et al-Braunwald's heart disease _ a textbook of cardiovascular medicine-Elsevier Saunders (2012)

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