Abnormal changes in transmitral flow after acute exposure to nitroglycerin and nifedipine in uncomplicated insulin-dependent diabetes mellitus: a Doppler echocardiographic study.
To study the left ventricular (LV) diastolic function in uncomplicated insulin-dependent diabetic patients without hypertension (n = 25) and comparable controls (n = 15), the effect of acute administration of nitroglycerin and nifedipine on cavity dimensions and transmitral flow pattern was investigated by Doppler echocardiography. At baseline no significant differences in any of the LV Doppler echocardiographic parameters were seen in the two groups. Only in diabetics did nitroglycerin diminish LV diastolic and systolic diameter significantly (p < 0.0002 and 0.004, respectively), reducing the stroke volume from 70 +/- 16 to 64 +/- 20 ml, p < 0.01. The decrease in stroke volume correlated significantly to hemoglobin (Hb) A1c level (r = 0.42, p = 0.036). An excessive preload reducing effect on venous capacitance vessels is assumed in diabetes, and this preload reducing effect was also reflected in transmitral flow pattern where E-wave/A-wave ratio decreased significantly only in the diabetic subjects (p < 0.0005). Nifedipine induced the same degree of sympathetic activation in the two groups, but an increase in LV early peak filling rate (E wave) was seen in diabetes only (63.3 +/- 13.5 to 66.8 +/- 13.5 mm, p < 0.01). The atrial filling of LV (A wave) was increased significantly in both groups. Thus an abnormal LV diastolic function can be disclosed by these pharmacologic challenges. Regulation of preload and its influence on transmitral flow pattern in diabetes deserves further investigation, as does the influence of calcium antagonists on early relaxation in the diabetic myocardium.
Gøtzsche
O
O
University Department of Cardiology, Arhus, Denmark.
Sihm
I
I
Lund
S
S
Schmitz
O
O
D000328:Adult; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003971:Diastole / Q000187:drug effects; D015150:Echocardiography, Doppler; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009543:Nifedipine / Q000494:pharmacology*; D005996:Nitroglycerin / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects*
D005996:Nitroglycerin; D009543:Nifedipine