Normal left ventricular performance documented by Doppler echocardiography in patients with long-standing hypocalcemia.

INTRODUCTION

Several reports suggest significantly reduced left ventricular performance in subjects with chronic hypocalcemia. We prospectively investigated eight patients, aged 13 to 31 years, with long-standing hypocalcemia due to idiopathic hypoparathyroidism or pseudohypoparathyroidism by echocardiography.

PATIENTS AND

METHODS

Six subjects had symptomatic hypocalcemia manifested as recurrent tetany (four), seizures (four), mental retardation (three), behavior disorder (one), and skeletal abnormalities (four); three subjects were untreated when studied. None had cardiovascular symptoms. Each patient underwent clinical, biochemical, and cardiac studies, including Doppler, two-dimensional, and M-mode echocardiography, on the same day.

RESULTS

In serum, both total and ionized calcium concentrations were reduced and averaged 7.2 mg/dl (range: 5.3 to 8.5 mg/dl; normal: 9.0 to 10.3 mg/dl) and 3.6 mg/dl (range: 3.0 to 3.9 mg/dl; normal: 4.5 to 5.3 mg/dl), respectively. Electrocardiograms revealed prolonged QTc intervals in six patients. Also noted were prominent U waves (five), T-wave abnormalities (four), and right-axis deviation (one). Resting echocardiography, however, demonstrated normal left ventricular function in all subjects. All M-mode measurements were normal. Two-dimensional-derived left ventricular end-diastolic and end-systolic volumes were 87.1 +/- 20.1 ml and 30.2 +/- 9.7 ml (mean +/- SD), respectively. Left ventricular ejection fraction was 65 percent (61.2 to 74.7 percent). Doppler-derived cardiac output and cardiac index averaged 5.1 liters/minute (2.9 to 6.7 liters/minute) and 3.0 liters/minute/m2 (1.7 to 4.3 liters/minute/m2), respectively.

CONCLUSION

Our prospective study of eight subjects with functional hypoparathyroidism demonstrated that, despite electrocardiographic abnormalities, long-standing hypocalcemia was not associated with left ventricular dysfunction.