Myocardial beta adrenoceptors and left ventricular function in hypertrophic cardiomyopathy.
Key result
Myocardial beta adrenoceptor density was significantly lower in patients with hypertrophic cardiomyopathy compared to normal controls (7.00 vs 11.50 pmol/g; P<0.01).
Why the study?
Is there a relationship between left ventricular function and myocardial beta adrenoceptor density in patients with hypertrophic cardiomyopathy?
Population
17 patients with hypertrophic cardiomyopathy and normal controls
Design
Cross-sectional
Authors
Discussion
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Implication
Downregulation may link to LV dysfunction in HCM; hypothesis-generating, requiring prospective confirmation before clinical consideration.
Key Points
- To evaluate the relationship between left ventricular function and myocardial beta adrenoceptor density in hypertrophic cardiomyopathy.
- 17 patients with hypertrophic cardiomyopathy examined, including 6 with heart failure and 11 without.
- Echocardiography measured left ventricular function; positron emission tomography assessed myocardial beta adrenoceptor density.
- Data compared against normal control values.
- Myocardial beta adrenoceptor density was significantly lower in patients (7.00 pmol/g) than in controls (11.50 pmol/g; P < 0.01).
- In patients with heart failure, beta adrenoceptor density was lower (5.61 pmol/g) compared to those with normal function (7.71 pmol/g; P < 0.05).
- Significant correlations found between beta adrenoceptor density and both left ventricular fractional shortening (r = 0.52; P < 0.05) and E/A transmitral flow ratio (r = 0.51; P < 0.05).
Study Design
Type
Observational (n=17)
Structured PICO
Is there a relationship between left ventricular function and myocardial beta adrenoceptor density in patients with hypertrophic cardiomyopathy?
P
Population
17 patients with hypertrophic cardiomyopathy (6 with heart failure, 11 without heart failure) and normal controls
C
Comparator
Normal controls
O
Outcome
Myocardial beta adrenoceptor density and its correlation with left ventricular function (fractional shortening and E/A ratio)surrogate
Main Result
Absolute Event Rate: 7% vs 11.5%
p-value: p=< 0.01
Myocardial beta adrenoceptors are downregulated in patients with hypertrophic cardiomyopathy, and this downregulation correlates with both systolic and diastolic left ventricular dysfunction.
Cite This Study
Choudhury et al. (1996) conducted an observational in Hypertrophic cardiomyopathy (n=17). Hypertrophic cardiomyopathy vs. Normal controls was evaluated on Myocardial beta adrenoceptor density (p=< 0.01). Myocardial beta adrenoceptor density was significantly lower in patients with hypertrophic cardiomyopathy compared to normal controls (7.00 vs 11.50 pmol/g; P<0.01).