Regional myocardial ischemia in hypertrophic cardiomyopathy: impact of myectomy.
OBJECTIVE
Chest pain is a common finding in patients with hypertrophic cardiomyopathy and can be observed in 40% to 50% of all patients. However, the pathogenesis of these ischemia-like symptoms is still unclear.


METHODS
Twenty-two patients with hypertrophic cardiomyopathy and 15 controls underwent positron emission tomography for evaluation of regional myocardial perfusion and coronary flow reserve (hyperemic/baseline myocardial blood flow). Myocardial perfusion (mL/min/g) was measured using [(13)N]ammonia at rest and during hyperemia with dipyridamole (0.56 mg/kg intravenously). Regional coronary flow reserve was assessed in 3 planes (apical, midventricular, basal) in 4 regions (septal, anterior, lateral, inferior). Patients were divided into 2 groups: group 1 consisted of 11 patients treated with surgical myectomy (age 56 +/- 10 years) and group 2 consisted of 11 patients treated medically (age 53 +/- 13 years).


RESULTS
Mean global coronary flow reserve was 3.87 +/- 0.92 in controls but 2.31 +/- 0.40 in operated (P <.001 vs controls) and 1.76 +/- 0.58 in medically treated patients (P <.001 vs controls, P <.05 vs operated). Similarly, septal coronary flow reserve was 4.19 +/- 1.22 in controls but significantly reduced in operated patients (2.26 +/- 0.48, P <.001 vs controls) and in medically treated patients (1.76 +/- 0.58; P <.001 vs controls). However, septal flow reserve was significantly higher in operated patients than in patients with medically treated hypertrophic cardiomyopathy (+37%, P <.05), mainly due to a reduced resting myocardial perfusion.


CONCLUSIONS
Global and regional myocardial perfusion is reduced in patients with hypertrophic cardiomyopathy. However, myectomy may have a beneficial effect on septal perfusion and flow reserve. Thus, ischemia seems to play an important role in the symptomatology and pathophysiology of hypertrophic cardiomyopathy.
Department of Cardiology, University Hospital, Ramistrasse 100, CH-8091 Zürich, Switzerland.
Manuela
M
Jörg-Ciopor
Mehdi
M
Namdar
Jurai
J
Turina
Rolf
R
Jenni
Jürg
J
Schwitter
Marko
M
Turina
Otto M
OM
Hess
Philipp A
PA
Kaufmann
D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000503:physiopathology / Q000601:surgery*; D003326:Coronary Circulation; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000209:etiology*