Echocardiographic evaluation of right heart responses to sublingual nifedipine in dilated cardiomyopathy.
Twelve patients with dilated cardiomyopathy were studied in order to evaluate whether the favourable effect of Nifedipine on the right heart is due to a direct action of the drug on pulmonary resistances or is related to an improvement of left ventricular function. Echocardiographic examination of left and right heart was performed at basic conditions, after Nifedipine treatment--20 mg sublingually--and after 20 minutes of oxygen breathing (FiO2 75%). This was done in order to verify if oxygen vasodilating action could potentiate the Nifedipine effect. Echocardiographic date were obtained in basic conditions, 10, 20 and 30 minutes after Nifedipine and immediately after oxygen breathing. Ten normal subjects were used for comparison for basic data. Peak Nifedipine activity was observed 10 minutes after administration. At this time inferior vena cava emptying index and systolic pulsation were significantly increased, whereas left and right ventricle isometric contraction time, left and right ventricle ejection time, left and right ventricle isovolumetric relaxation time, end-diastolic left ventricular diameter, inferior vena cava diameters and systolic blood pressure had decreased, thus showing the favourable effect of Nifedipine of both heart sides. Heart rate did not significantly change. Oxygen inhalation induced a significant decrease of right ventricular isovolumetric relaxation and an increase of the inferior vena cava indexes, suggesting an improvement in right heart function, without any change in other parameters. No significant difference was found between data after-oxygen and data obtained 10' after Nifedipine, showing that the Nifedipine effect was not potentiated by oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)
Gullace
G
G
Divisione di Cardiologia, Ospedale di Lecco, USSL n. 16, Italy.
Mancini
R
R
Ravizza
P
P
Locatelli
V
V
Addamiano
P
P
Ferracini
C
C
Gerosa
C
C
Bana
G
G
Savoia
M T
MT
Knippel
M
M
D000286:Administration, Sublingual; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002311:Cardiomyopathy, Dilated / Q000188:drug therapy* / Q000503:physiopathology; D003326:Coronary Circulation / Q000187:drug effects; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage / Q000494:pharmacology*; D010102:Oxygen Inhalation Therapy; D011652:Pulmonary Circulation / Q000187:drug effects*
D009543:Nifedipine