STUDY OBJECTIVE: To determine the prevalence of left ventricular diastolic dysfunction in patients with biopsy specimen-proved pulmonary sarcoidosis without clinical evidence of cardiac disease. DESIGN: A cross-sectional study. SETTING: A large tertiary care university teaching hospital. PATIENTS AND CONTROL SUBJECTS: Fifty consecutive subjects had biopsy specimen-proved pulmonary sarcoidosis without suspected cardiac involvement. Those with other conditions known to affect diastolic function were excluded. The control group comprised 30 healthy hospital workers. INTERVENTIONS: Clinical examination, 12-lead ECG, and combined echocardiographic/phonocardiographic examination. MEASUREMENTS: Indexes of left ventricular diastolic function, including isovolumic relaxation time, peak velocity of early (E) and late (A) ventricular filling, deceleration rate of early diastolic flow, and the sum of the time velocity integrals of E and A were obtained in each patient and control subject. Systolic function was determined using a modification of Simpson's rule. RESULTS: Diastolic dysfunction was present in 7 (14%) patients, 6 of whom had normal systolic function and normal two-dimensional echocardiographic examination. Those with diastolic dysfunction had a longer duration of illness (15 +/- 7 vs 6 +/- 5 years; p = 0.0004), were significantly older (52 +/- 11 vs 38 +/- 9 years; p = 0.0009), and had higher systolic BP (130 +/- 13 vs 117 +/- 12 mm Hg; p = 0.01) than the sarcoid patients with normal diastolic function. CONCLUSIONS: These results demonstrate a significant prevalence of left ventricular diastolic dysfunction in patients with pulmonary sarcoidosis. The cause of this abnormality may be a subclinical sarcoid cardiomyopathy.