Left Ventricular Hypertrophy Detection, significance and treatment

Pathophysiology of LVH l High BP   LV wall stress l Wall stress  1/ wall thickness l LV wall thickening   wall stress l Myocyte hypertrophy and  collagen matrix l Mediators: l Mechanical: preload & afterload l Neurohormonal: angiotensin II, sympathetic NS

Methods of detecting LVH l Clinical examination l Chest radiography l Electrocardiography l Echocardiography l (CT, MRI)

Definition of LVH l Healthy cohort of subjects l No high BP, diabetes, CV disease, obesity l LVH defined as LVMI > mean + 2SD l Framingham Study LVMI > 131g/m 2 males; > 100g/m 2 females l Cornell, New York LVMI > 134g/m 2 males; > 110g/m 2 females Levy et al. Am J Cardiol 1987;59: Devereux et al. JACC 1984;4:

Risk factors for LVH l Age l Gender l Race l Genetic factors l Blood pressure l Obesity l Physical activity

Clinic versus mean 24 hour systolic BP and LVMI Mayet al et. J Cardiovasc Risk 1995;2:

12-lead ECG showing LVH and strain

Sensitivity and specificity of ECG criteria for LVH Devereux et al 1983, Murphy et al 1985, Levy et al 1990, Lee et al 1992, Devereux et al 1993, Schillaci et al 1994, Crow et al 1995, Norman et al 1995, Chapman et al (in press)

Determinants of specificity of ECG criteria for LVH l Age l Race l Sex l Smoking l Obesity

Cardiothoracic ratio and CHD mortality: Whitehall study *Adjusted for age, BP, HR, cholesterol, smoking, angina and ECG ischaemia Hemingway et al. BMJ 1998; 316:

Cardiovascular risk in subjects with ECG-LVH: Framingham Age-adjusted risk-ratio *P< Kannel. Eur Heart J 1992; 13 (suppl D): 82-88

Risks of X-ray and ECG LVH: Framingham Data include men and women, aged Age-adjusted biennial rate per 1000 Kannel. Eur Heart J 1992; 13 (suppl D): 82-88

Echocardiography l Advantages l sensitivity l improved correlation with morbidity & mortality l assessment of function (systolic and diastolic) l addition to individual’s risk profile l Disadvantages l skilled operator l time l cost

Echocardiographic LVH and prognosis Sheps and Frohlich. Hypertension 1997; 29:

M-mode echocardiograms LVHNormal

Penn convention for M-mode measurements l Peak of QRS l Endocardium excluded from SWT and PWT l Endocardium included in LVID LV mass = 1.04[(SWT+LVID+PWT) 3 - (LVID) g Divide by body surface area to get LV mass index LV cavity (LVID) Septum (SWT) Posterior wall (PWT) Devereux & Reichek Circulation 1977;55:613-8

ASE guidelines for M-mode measurements l Start of QRS l Endocardium included in SWT and PWT l Endocardium excluded from LVID LVM = 0.8{1.04[ (SWT+LVID+PWT) 3 - (LVID) 3 ]} g Divide by body surface area to get LV mass index LV cavity (LVID) Septum (SWT) Posterior wall (PWT) Devereux et al. Am J Cardiol 1986;57:450-8

Area-length method for calculation of LV mass LVmass=1.05[5/6(A1xL1)-5/6(A2xL2)] Divide by body surface area to get LV mass index Reichek et al. Circulation 1983;67:348-52

4-year age-adjusted incidence of cardiovascular disease according to LVMI LVMI (g/m 2 ) Age-adjusted incidence/ 100 subjects Redrawn from Levy et al; NEJM 1990; 322:

Incidence of cardiovascular mortality according to presence or absence of LVH 4-year age-adjusted cardiovascular mortality P<0.001 P=ns Redrawn from Levy et al, NEJM 1990; 322:

Echocardiographic LVH and prognosis Sheps and Frohlich. Hypertension 1997; 29:

Risks associated with LVM and geometry LVMI (g/m 2 ) RWT Total mortality* Cardiovascular events † % patients Koren et al. Ann Int Med 1991; 114: *P<0.001, † P=0.03

Regression of LVH by drug treatment: meta-analysis of RCTs Schmieder et al. JAMA 1996; 275: Mean %  in LVMI Between treatment P<0.01

LVH regression: LIVE study *P<0.05 for LVMI * %  from baseline Sheridan and Gosse 1998

Prognostic significance of Echo LVM regression Events/ 100 patient years Verdecchia et al. Circulation 1998; 97: * † *P=0.04, †P= after adjustment for age.

Prognostic significance of ECG voltage changes: Framingham OR for CV events (2 years) * * *P<0.05 Levy et al. Circulation 1994; 90:

Who to refer for echocardiography? l Patients with borderline BP: l LVH may influence decision to treat l Patient with multiple risk factors: l LVH may lead to other interventions e.g. lipid lowering therapy l Possible white coat hypertension l ? To stratify class of antihypertensive agent to be used (increasing data suggesting LVH regression should be a goal of treatment)