Biomedical subjects

A Toruncha

Publications and source records attributed to A Toruncha.

8 recordsLinked to original sources

PubMed1985

Comparison of segmental and global ejection fraction in ischaemic heart disease.

In order to evaluate whether segmental ejection fraction (SEF) is a better index of left ventricular (LV) performance than global ejection fraction (EF), 25 patients with significant coronary stenosis and normal EF were studied. SEF was estimated from the LV cineangiogram after dividing the LV into eight segments by means of a long axis and three equally spaced chords perpendicular to it. The area of a given segment was measured in the end-diastole and the end-systole and SEF was calculated by determining the percent decrease in area for each segment. 12 out of the 25 patients presented hypokinesis, akinesis or dyskinesis of at least two segments; the inferior apical and both diaphragmatic segments were the regions most frequently affected. In 7 patients, these abnormalities were compensated by hyperkinesis of two or three other segments, whereas in the remaining 5 patients contraction abnormalities were not accompanied by hyperkinesis in spite of a normal EF. It is concluded that SEF is a more sensitive index of regional LV function than EF in patients with ischaemic heart disease.

Coronary Disease↗

PubMed1983

Segmental ejection fraction in normal subjects.

Following a modification of the area method described by Gelberg et al., left ventricular regional wall motion was studied in 30 normal subject. The left ventricular cineangiograms were filmed in the right anterior oblique projection at 48 frames/s after injection of 76% sodium-meglumine diatrizoate. The end-diastolic and end-systolic frames were each divided into 8 regions using a grid formed by longitudinal axis, which was traced from the midpoint of the aortic valve to the apex, and three equally spaced perpendiculars to the long axis. Segmental ejection fraction was estimated by determining the percent decrease in each segment area in end-systole with respect to the end-diastolic area. The mean values +/- S. D. obtained for each segment were: anterobasal 58 +/- 14%; anterolateral-proximal 59 +/- 6%; anterolateral-distal 58 +/- 4%; apical-superior 59 +/- 8%; apical-inferior 58 +/- 7%; diaphragmatic-distal 58 +/- 9%; diaphragmatic-proximal 55 +/- 6%; and posterobasal 42 +/- 15%. The values obtained are useful for comparison when evaluating left ventricular performance in patients.

Cardiac Output↗

PubMed1982

Effects of oral atenolol and propranolol on blood pressure, heart rate and plasma cyclic adenosine 3':5'-monophosphate in borderline hypertensive patients.

The effects of oral treatment with atenolol and propranolol on blood pressure, heart rate and plasma cyclic adenosine 3':5'-monophosphate (cAMP) were studied in a group of young borderline hypertensives. Observations were accomplished after a period of recumbent relaxation and also following physiological stress testing. The latter significantly increased blood pressure, heart rate and plasma cAMP. A direct relationship was found between heart rate and plasma cAMP at rest and also following psychological stress. This relationship was lost following drug treatments. Both beta-blockers significantly reduced all measured variables in both conditions. However, plasma cAMP was most affected by propranolol.

Adolescent↗

PubMed1982

Oral amiodarone in high-risk ventricular arrhythmias.

Oral amiodarone was evaluated in 24 patients with complex forms of ventricular premature depolarizations (VPD) by means of ECG monitoring and measurement of systolic time intervals. The patients received 800 mg daily for 3 days, 600 mg daily for 7 days and 400 mg daily thereafter. Follow-up lasted from 6 to 17 months. Advanced forms of VPD were abolished and the VPD rate was reduced in 98% of patients. After 10 days repetitive VPD were absent in more than 80% and after 4 months more than 70% were completely free from arrhythmia. ECG changes revealed heart rate reduction and prolongation of PR, QRS and QTc intervals. Left ventricular performance was not influenced. After 6 months of treatment, 10 randomly selected patients received placebo instead of amiodarone in a single blind fashion until arrhythmia reappeared; the latter was again abolished by reinstituting amiodarone, The most frequent side effect were corneal microdeposits which were reversible and did not impair vision. It is concluded that amiodarone is effective and well tolerated in patients with high-risk VPD.

Administration, Oral↗

PubMed1979

Reversion of supraventricular tachyarrhythmias by means of atrial stimulation.

Thirteen patients with different forms of supraventricular tachyarrhythmia were treated by means of right atrial pacing. Reversion of arrhythmia was obtained in nine out of ten patients with atrial tachycardia or flutter. The remaining three patients, with atrial fibrillation, did not respond to the procedure. The effective pacing rate in converting arrhythmia ranged from 110 to 2400/min, however in five cases it was lower than the atrial rate. The duration of pacing at an effective rate ranged from 20 seconds to 5 minutes in 5 cases, while in the remaining patients it lasted 10 minutes. In two patients the original arrhythmia was converted to atrial fibrillation during stimulation, but in one it disappeared with pacing at 110/min, and in the other, reversion to sinus rhythm occurred spontaneously 4 hours later. No complications were observed. It is concluded that atrial pacing may be useful aid to treat paroxysmal atrial tachycardia or flutter, and can be considered as an alternative procedure whenever there is no response to customary medical treatment or when transthoracic direct current cardioversion is potentially dangerous.

Adult↗

PubMed1979

Influence of post-extrasystolic potentiation on left ventricular function estimated by means of systolic time intervals.

Systolic time intervals were measured in 50 patients with frequent premature ventricular beats. The patients were divided into two groups: group I included those which showed in the beat that preceded an extrasystole a pre-ejection period/left ventricular ejection time (PEP/LVET) ratio greater than or equal to 0.43, and group II with PEP/LVET ratio greater than 0.44. Systolic time intervals recorded during post-extrasystolic potentiation were compared with those measured in the preextrasystolic complex. Also the measured intervals were tested against the hourly rate of premature beats obtained by electrocardiographic telemetric monitoring. The results confirmed the following results of previous reports: a) ventricular premature beats are followed by sinus-potentiated contractions inversely related to the coupling interval and dependent on adequate compensatory pauses; b) potentiated contractions are greater in patients with ventricular dysfunction. No relationship was found between left ventricular performance and the rate of premature beats. It is concluded that the effect of an antiarrhythmic intervention on the left ventricular function might be adequately evaluated by means of systolic time intervals and provoked post-extrasystolic potentiation, with the advantage of using totally non-invasive procedures.

Cardiac Complexes, Premature↗

PubMedDate not supplied

Acute oral antiarrhythmic testing with disopyramide.

Acute antiarrhythmic drug testing with disopyramide was accomplished in 25 patients with frequent ventricular premature depolarization (VPD). Systolic time intervals (STI) were used to assess left ventricular performance. Eighteen patients responded after a loading oral dose of 300 mg disopyramide with 80% or greater reduction in VPD and abolition of advanced grades. Mean onset of drug action was 93 min and the mean plasma level at 2 h was 3.4 microgram /ml. During maintenance therapy 2 of the 18 patients had a relapse, In 2 others, initially protected, VPD recurred during both exercise and psychological stress testing. STI showed increments in pre-ejection period (PEP) and in PEP/ejection time ratio at peak concentrations of plasma disopyramide. Acute tests repeated with placebo in a single-blind fashion in responding patients failed to significantly reduce VPD frequency or grade. Side effects consisted of anticholinergic actions of disopyramide. In 3 patients aggravation of heart failure compelled discontinuation of disopyramide which then remitted.

Acute Disease↗

PubMedDate not supplied

Enhancement of the antiarrhythmic action of disopyramide by digoxin.

Acute antiarrhythmic testing with 200 mg of disopyramide p.o. was performed in two groups of 15 patients each, with a prevalence of ventricular premature depolarization (VPD) exceeding one per minute. Patients in the first group were not receiving cardiac glycosides; those in the second group were on maintenance therapy with oral digoxin. Systolic time intervals (STI) were recorded throughout the test in order to evaluate left ventricular performance. Plasma levels of disopyramide were measured at peak ECG changes and digoxin levels before and 2 h following administration of disopyramide. Only five patients in the first group responded with an 80% or greater reduction in VPD rate and abolition of repetitive forms. In contrast, 13 digitalized patients responded to disopyramide. Mean plasma levels of disopyramide did not differ in the two groups (1.68 and 1.78 microgram/ml, respectively). Digoxin plasma levels in no case exceeded 3 ng/ml and did not change significantly after disopyramide. Significant increases in STI and in the QTC interval were recorded only in patients of the first group. The PR interval was prolonged in both groups, but to a greater extent in patients receiving digoxin. We conclude that digitalization may prevent myocardial functional depression caused by disopyramide and enhance its antiarrhythmic action.

Adult↗