Transcript Definition of LVH

Left Ventricular Hypertrophy
Detection, significance and treatment
Pathophysiology of LVH
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High BP   LV wall stress
Wall stress  1/ wall thickness
LV wall thickening   wall stress
Myocyte hypertrophy and  collagen matrix
Mediators:
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Mechanical: preload & afterload
Neurohormonal: angiotensin II, sympathetic NS
Methods of detecting LVH
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Clinical examination
Chest radiography
Electrocardiography
Echocardiography
(CT, MRI)
Definition of LVH
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Healthy cohort of subjects
No high BP, diabetes, CV disease, obesity
LVH defined as LVMI > mean + 2SD
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Framingham Study
LVMI > 131g/m2 males; > 100g/m2 females
Cornell, New York
LVMI > 134g/m2 males; > 110g/m2 females
Levy et al. Am J Cardiol 1987;59:956-60.
Devereux et al. JACC 1984;4:1222-30.
Risk factors for LVH
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Age
Gender
Race
Genetic factors
Blood pressure
Obesity
Physical activity
Clinic versus mean 24 hour
systolic BP and LVMI
Relationship between mean 24 hour SBP and LVMI
Linear (Relationship between mean 24 hour SBP and LVMI)
Linear (Relationship between mean 24 hour SBP and LVMI)
Clinic SBP v. LVMI: (r=0.28,
p<0.05)
24 hour mean SBP v. LVMI
(r=0.48, p<0.01)
24 hour SBP (mmHg)
Clinic SBP
(mmHg)
250
200
150
100
50
0
0
100
200
LVMI (g/m2)
300
250
200
150
100
50
0
0
100
200
300
LVMI (gm2)
Mayet al et. J Cardiovasc Risk 1995;2:255-61.
12-lead ECG showing LVH and strain
Sensitivity and specificity of ECG criteria for LVH
Sensitivity Specificity
Sokolow-Lyon
15-30
73-100
Cornell voltage
7-45
93-100
Romhilt-Estes point score 6-50
85-99
Minnesota code 3-1
3-15
88-99
Framingham criteria
3-17
98-100
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
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Age
Race
Sex
Smoking
Obesity
Cardiothoracic ratio and CHD mortality:
Whitehall study
Cardiothoracic ratio Hazard ratio for CHD*
<0.4
1.0
0.4-0.439
1.02 (0.61-1.73)
0.44-0.449
1.02 (0.60-1.74)
0.45-0.469
1.33 (0.81-2.20)
0.47-
1.65 (1.01-2.70)
*Adjusted for age, BP, HR, cholesterol, smoking, angina and ECG ischaemia
Hemingway et al. BMJ 1998; 316: 1353-4.
Cardiovascular risk in subjects with ECG-LVH:
Framingham
Age-adjusted risk-ratio
Cardiovascular outcome
Men
Women
Coronary heart disease
Stroke
Peripheral arterial disaese
Cardiac failure
3.0*
5.8*
2.7
15.0*
4.6*
6.2*
5.3*
12.8*
*P<0.0001
Kannel. Eur Heart J 1992; 13 (suppl D): 82-88
Risks of X-ray and ECG LVH:
Framingham
Age-adjusted biennial rate per 1000
No X-ray enlargement X-ray enlargement
No ECG-LVH
171
253
ECG-LVH
669
1072
Data include men and women, aged 35-94
Kannel. Eur Heart J 1992; 13 (suppl D): 82-88
Echocardiography
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Advantages
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sensitivity
improved correlation with morbidity & mortality
assessment of function (systolic and diastolic)
addition to individual’s risk profile
Disadvantages
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skilled operator
time
cost
Echocardiographic LVH and prognosis
Ref.
Population N
Follow-up End-points RR with LVH
Levy et al 1990
General
1911 4y
CAD
Levy et al 1989
General
3220 4y
CVD
All death
Men: 1.67
Women 1.60
Men 1.49
Women 1.57
Men 1.73
Women 2.12
Men 3.83
Casale et al 1986 HTN
140
4.8y
CVD
Koren et al 1991 HTN
280
10.2y
CVD
All 2.17
CVD death All 14.0
All death
All 3.5
Sheps and Frohlich. Hypertension 1997; 29: 560-563.
M-mode echocardiograms
LVH
Normal
Penn convention for M-mode
measurements
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Septum (SWT)
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Peak of QRS
Endocardium excluded from SWT
and PWT
Endocardium included in LVID
LV cavity (LVID)
LV mass = 1.04[(SWT+LVID+PWT)3 - (LVID)3 - 14g
Posterior wall (PWT)
Divide by body surface area to get LV mass index
Devereux & Reichek Circulation 1977;55:613-8
ASE guidelines for M-mode
measurements
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Septum (SWT)
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Start of QRS
Endocardium included in SWT and
PWT
Endocardium excluded from LVID
LV cavity (LVID)
LVM = 0.8{1.04[ (SWT+LVID+PWT)3 - (LVID)3]} + 0.6 g
Posterior wall (PWT)
Divide by body surface area to get LV mass index
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
18
16
14
12
10
Males
Females
8
6
4
2
0
<75
75-94
95-116
117-
LVMI (g/m2)
Redrawn from Levy et al; NEJM 1990; 322: 1561-6.
Incidence of cardiovascular mortality
according to presence or absence of LVH
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
No LVH
LVH
Men
P<0.001
Women
P=ns
Redrawn from Levy et al, NEJM 1990; 322: 1561-6.
Echocardiographic LVH and prognosis
Ref.
Population N
Follow-up End-points RR with LVH
Levy et al 1990
General
1911 4y
CAD
Levy et al 1989
General
3220 4y
CVD
All death
Men: 1.67
Women 1.60
Men 1.49
Women 1.57
Men 1.73
Women 2.12
Men 3.83
Casale et al 1986 HTN
140
4.8y
CVD
Koren et al 1991 HTN
280
10.2y
CVD
All 2.17
CVD death All 14.0
All death
All 3.5
Sheps and Frohlich. Hypertension 1997; 29: 560-563.
Risks associated with LVM and geometry
Total mortality*
Cardiovascular events†
% patients
40
30
20
>0.45
<0.45
10
0
>125
<125
LVMI (g/m2)
*P<0.001, †P=0.03
>125
<125
RWT
LVMI (g/m2)
Koren et al. Ann Int Med 1991; 114: 345-352.
Regression of LVH by drug treatment:
meta-analysis of RCTs
0
-2
-4
-6
-8
-10
-12
-14
Diuretics
B-blockers
CCB's
ACE-I
Between treatment P<0.01
Schmieder et al. JAMA 1996; 275: 1507-1513
LVH regression: LIVE study
1
% from baseline
0
-1
-2
-3
*
Indapamide SR
Enalapril
-4
-5
*P<0.05 for LVMI
-6
PWT
IVST
LVID
LVMI
Sheridan and Gosse 1998
Events/ 100 patient years
Prognostic significance of Echo LVM regression
7
6
5
4
†
3
2
*
1
0
All
LVH
Regressors
Non-regressors
*P=0.04, †P=0.0004 after adjustment for age.
Verdecchia et al. Circulation 1998; 97: 48-54
OR for CV events (2 years)
Prognostic significance of ECG voltage
changes: Framingham
2
1.5
*
1
0.5
*
0
Decreased voltage
Increased voltage
Males
*P<0.05
Females
Levy et al. Circulation 1994; 90: 1786-1793
Who to refer for echocardiography?
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Patients with borderline BP:
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Patient with multiple risk factors:
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LVH may influence decision to treat
LVH may lead to other interventions e.g. lipid
lowering therapy
Possible white coat hypertension
? To stratify class of antihypertensive agent to
be used (increasing data suggesting LVH
regression should be a goal of treatment)