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Biomedical subjects

M Grbic

Publications and source records attributed to M Grbic.

29 records · Page 2Linked to original sources
PubMed1985

Conversion of supraventricular arrhythmias to sinus rhythm using flecainide.

We evaluated the efficacy of flecainide acetate (given intravenously to a maximal dose of 2 mg kg-1 and then orally in a dose of 100 mg b.d. or 100 mg t.d.s.) in the conversion to sinus rhythm of 50 patients exhibiting supraventricular arrhythmias (39 with atrial fibrillation, 6 with atrial flutter, 4 with supraventricular tachycardia and one with supraventricular tachycardia in association with the Wolff-Parkinson-White syndrome). Conversion was achieved in 36 patients (72%) (29 cases with atrial fibrillation, 4 cases with supraventricular tachycardia, 2 cases with atrial flutter and one case with Wolff-Parkinson-White syndrome), over a mean period of 7.4 +/- 9 h. The patients in which conversion was achieved had arrhythmias which had been in existence for a shorter time (5.3 +/- 9.8 days) than those in which conversion was not achieved (16.7 +/- 26.2 days) (P less than 0.01). The mean dosage of flecainide used to achieve conversion was 2.5 +/- 2.36 mg kg-1. Flecainide appears to be an effective agent for the conversion to sinus rhythm of atrial fibrillation and supraventricular tachycardias. Its efficacy in cases of atrial flutter has not yet been demonstrated.

Adult↗
PubMed1983

[Percutaneous transluminal angioplasty in patients with recurrent angina following aorto-coronary bypass].

Twenty patients presenting with angina pectoris after coronary bypass surgery underwent percutaneous transluminal coronary angioplasty (PTCA). Twenty-six PTCA were carried out, 15 on stenosed bypasses, 10 on stenosed coronary arteries and 1 on an occluded bypass. PTCA results were very good in 85% of cases and satisfactory in another 10%. Clinically, 90% of patients improved. In view of these data, PTCA should be considered a viable alternative to surgical reintervention.

Angina Pectoris↗
PubMed1983

[Left ventricular function following revascularization for occlusion of a coronary artery lasting 1 to 2 hours].

The time-lag between coronary occlusion and irreversible damage to the myocardium is ill-defined in man. In 10 patients the changes in left ventricular function have been studied after coronary occlusion during diagnostic or therapeutic cardiac catheterization of 1-2 hours' duration. Revascularization was achieved either surgically or through intracoronary streptokinase infusion. The interval between occlusion and onset of extracorporal circulation or reopening was 61 to 119 minutes. Despite enzyme elevation (CPK, CK-MB, SGOT) and appearance of Q-waves in 5 patients, no significant alteration of left ventricular function was noted on repeat cardiac catheterization 10 to 230 days after the accident. These observations, suggest that coronary occlusion of 1-2 hours' duration fails to produce significant irreversible damage to the myocardium despite electrocardiographic and enzymatic signs of myocardial infarction.

Aspartate Aminotransferases↗
PubMed1983

[Intracoronary thrombolysis as a treatment for evolving myocardial infarction].

Myocardial infarction is almost always the consequence of a thrombotic obstruction of one or more coronary arteries. We report our experience with the first 24 cases of intracoronary thrombolysis for recanalization of obstructed coronary arteries. 19 cases were successful, 1 case was partially successful and in 4 instances no reopening was observed. The amount of streptokinase used was 206 000 +/- 107 000 units, and reperfusion was achieved after 37 +/- 27.5 minutes. Recanalization of the vessel was accompanied by cessation of precordial pain and partial or complete normalization of the electrocardiogram. In one case bypass surgery was necessary because of reocclusion. Left ventricular function improvement after thrombolysis was dependent on the time-lag between occlusion and recanalization. These observations confirm others' experience that intracoronary thrombolysis appears to have favorable effects in patients with evolving myocardial infarction.

Coronary Disease↗
PubMed1983

[Congestive cardiomyopathy: value of short and long-term vasodilator treatment and prognosis].

Vasodilator therapy in congestive heart failure has proven an effective adjunct to conventional treatment with digitalis and diuretics. In this study dipyridamole was used in combination with isosorbide dinitrate to treat twelve patients (mean age 55 years) with idiopathic congestive cardiomyopathy. All patients were in N.Y.H.A. class III or IV and were already treated with digitalis and diuretics. This conventional therapy was not discontinued for the study. Acute studies were performed during diagnostic right and left heart catheterization. Hemodynamics were obtained at rest, after intravenous administration of 40 mg dipyridamole and after 5 mg isosorbide dinitrate sublingually. An increase in cardiac index and stroke volume index was noted, while left ventricular enddiastolic pressure and systemic vascular resistance decreased significantly. The twelve patients were then treated with 4 X 150 mg dipyridamole and 4 X 40 mg isosorbide dinitrate per day while also continuing the digitalis and diuretic treatment. They were followed up clinically for a period of 8 to 24 months. Three patients died but the other nine showed a clinical improvement (mean of 1.45 N.Y.H.A. classes). It was possible to perform a second right and left heart catheterization in four patients. Cardiac index, stroke volume index and maximum and minimum DP/dt were significantly higher, and left ventricular enddiastolic pressure was significantly lower, than before vasodilator therapy. These results suggest a sustained effect of dipyridamole and isosorbide dinitrate. The postextrasystolic modification of maximum DP/dt could be of prognostic value in congestive cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Improvement of left ventricular function after percutaneous transluminal coronary angioplasty.

Cardiac function and left ventricular dynamics were measured in seven consecutive patients 1 day before and 6 months after percutaneous transluminal balloon angioplasty of subtotal proximal stenosis of the left anterior descending coronary artery. Before angioplasty all patients had obvious left ventricular dysfunction during exercise and to a smaller degree during isoproterenol infusion; the condition of all patients was greatly improved 6 months after angioplasty. After angioplasty, left ventricular end-diastolic pressure was normal at rest and decreased from a mean (+/- standard error of the mean) of 33.8 +/- 1.6 to 19.2 +/- 0.5 mm Hg on exercise. Left ventricular ejection fraction, measured by a gated blood pooling technique with technetium-99m, improved on exercise from 46 +/- 5.0 percent to 69 +/- 1.0 percent. Cardiac output and stroke volume index increased significantly with exercise after angioplasty. The peak negative rate of pressure reduction in the left ventricle (dP/dt/min), an index of left ventricular relaxation, was highly abnormal on exercise before (2,307 +/- 260 mm Hg/s) and increased to the normal range (3,154 +/- 200 mm Hg/s) after angioplasty. The improvement in left ventricular function after transluminal angioplasty in these cases of proximal left anterior descending coronary arterial stenosis is extremely encouraging.

Adult↗
PubMed1980

[Effect of dynamic exercise on left ventricular hemodynamics in obstructive cardiomyopathy].

The behavior of left ventricular (LV) outflow tract obstruction in hypertrophic obstructive cardiomyopathy (HOCM) during dynamic exercise was studied in 9 patients during cardiac catheterization. Pressure measurements were carried out with high fidelity tip manometers and cardiac output was measured by the thermodilution method. Resting intraventricular pressure gradients varied from 5 to 75 mm Hg (mean 41 +/- 30 mm Hg) and all patients had postextrasystolic gradients of more than 100 mm Hg. Under supine bicycle exercise (mean work load 80 watts) heart rate increased from 74 +/- 9 to 97 +/- 10 min-1, cardiac output rose from 4.32 +/- 0.7 to 8.36 +/- 2.0 l/min, and LV intraventricular pressure gradient dropped significantly to 16 +/- 4 mm Hg. This improvement of LV outflow tract obstruction was associated with an increase in LV enddiastolic pressure from 14 +/- 5 mm Hg to 25 +/- 2 mm Hg, an augmentation of dP/dt max from 1225 +/- 300 to 1748 +/- 200 mm Hg/sec and a deterioration of systolic to diastolic pressure-time index ratio. These preliminary results indicate partial normalization of the LV outflow tract obstruction in HOCM during supine bicycle exercise; this favorable effect is probably due to an increased enddiastolic LV volume.

Adult↗
PubMed1975

[Prinzmetal's angor. Apropos of 4 cases. Review of the literature].

In the light of 4 personal observations of PPPRINZMETAL's angina, a review has been conducted of the literature in the 15 years since the condition was first described. Although the formal diagnostic criteria for this form of angina simultaneously clinical, biological and electrical - anginal attacks occurring at rest, often at night, during which elevation of the ST segment is recorded which disappears at the end of the attack without any significant rise in enzyme levels (SGOT and CPK) - the frontiers of the syndrome appear to have widened since PRINZMETAL's description: - Severe proximal stenosis of the coronary arteries is not obligatory; they may be only slightly damaged or even healthy. - Prinzmetal's angina is by no means always "spontaneous" but is often induced, either by psychic factors, which explain the fixed time of the attacks, or by organic factors, e.g. cold drinks (Observation No.2). In this event it would appear safer to speak of angina or rest as opposed to angina of effort. - In contrast to what PRINZMETAL thought, effort tests may sometimes induce angina-type pain with elevation of the ST segment, and here the borderline between this syndrome and conventional angina with ST segment elevation after effort test (5% of cases) is less clear-cut. The two nosologic entities probably reflect the same physiopathological situation, i.e. acute myocardial ischemia, and may represent the same affection in different phases of development. The prognosis is equally bad. - Attacks of rinzmetal's angina are often accompanied by severe and sometimes fatal disorders of rhythm, and this influences the therapeutic approach. - The coronary spasm posited by PRINZMETAL and others before the advent of coronarography is indeed, in the majority of cases, the immediate cause of myocardial ischemia and anginal pain, without any preliminary increase in the energy requirements of the heart as in the conventional anginal attack. - A vasoactive substance present in the circulating blood at the beginning of the affection, which may be degraded and subsequently disappear and may be secreted by the pathologic coronary artery, was demonstrated in observation No. 4: this may, in conjunction with vagal hypertonia, be the causative factor in coronary spasm. Study of its pharmacodynamic properties is now in progress.

Adult↗
PubMedDate not supplied

Maternal expression and early zygotic regulation of the Hox3/zen gene in the grasshopper Schistocerca gregaria.

In insects, a key step in the early patterning of the egg is to distinguish the primordium of the embryo proper from those regions that will form extra-embryonic membranes. In Drosophila, where these processes are well understood, the structure of the extra-embryonic membranes is highly derived. The distinct amnion and serosa typical of lower insects is replaced by a single, fused, and much reduced membrane, the amnioserosa, which never secretes an embryonic cuticle. We have used the Zen gene as a marker to study the formation of the extra-embryonic membranes, and other aspects of early embryonic patterning, in the grasshopper Schistocerca gregaria (African Plague Locust). Zen genes are derived from Hox genes, but in Drosophila they appear to have lost any role in patterning the A/P axis of the embryo; instead, they are involved in D/V patterning and the specification of the extra-embryonic membranes. We show that the Schistocerca zen gene is expressed during embryogenesis in three distinct phases. The first of these is during cleavage, when Sgzen is transiently expressed in all energids that reach the cell surface. The second phase of expression initiates in a ring of "necklace cells" that surround the forming embryo, and demarcate the boundary between the amnion and serosa. This leads to expression throughout the serosa. The final phase of expression is in the amnion, after this has separated from the serosa. This complex pattern implies that the role of Sgzen in Schistocerca is not limited solely to the specification of cell identity in the extra-embryonic membranes. We also report that the Schistocerca zen gene is expressed maternally, unlike its Drosophila and Tribolium counterparts. A distinct maternal transcript, and maternal Zen protein, accumulate in the developing oocyte from early post-meiotic stages. They remain uniformly distributed in the oocyte cytoplasm until late vitellogenic stages, when the protein and RNA become somewhat concentrated at the egg cortex and in the posterior polar cap of the oocyte, probably by passive exclusion from the yolk. The cytoplasmic localization of Sgzen protein in the oocyte, and at some stages during embryogenesis, implies that nuclear exclusion of this transcription factor is specifically controlled.

Animals↗