Out of 127 directional coronary atherectomy (DCA) procedures done in our laboratory, there were 81 patients who had completed a minimum of six months of follow-up. To study the factors predisposing restenosis after successful DCA, we analysed the clinical and angiographic profile of the patients and the histopathological findings of the excised tissue in 44 patients whose complete follow-up data was available with us. The indication of DCA was an extremely eccentric significant stenosis located in the proximal or midsegment of a large vessel (> or = 3 mm size) in 97 percent of the cases. Angiographic restenosis, defined as more than 50 percent luminal diameter stenosis was absent in 24 (54.5%, Group A) and present in 20 (45.5%, Group B) patients. On univariate analysis, the factors which predisposed to restenosis were: (i) left anterior descending location, (ii) longer lesion length (9.6 +/- 3.1 mm vs 5.2 +/- 1.6, p < 0.01) and (iii) greater post-procedure residual luminal diameter stenosis (13.1 +/- 10.8% vs 4.3 +/- 6%, p < 0.01). No significant difference was found between the two groups for other variables like unstable angina, the location and the morphological characteristics of the lesion and the ratio of the vessel diameter to the size of the Atherocath. Histopathological examination of the retrieved tissue revealed the presence of media with or without external elastic lamina in 8 (33%) patients in Group A--without restenosis compared to only 1 (5%) patients in Group B--with restenosis (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Atherectomy, Coronary↗

PubMedDate not supplied

Electrophysiologic effects and therapeutic efficacy of intravenous flecainide for termination of paroxysmal supraventricular tachycardia.

Flecainide is a class IC antiarrhythmic agent with a controversial role in the treatment of ventricular arrhythmias following myocardial infarction after the publication of the Cardiac Arrhythmia Suppression Trial (CAST). To assess its utility in paroxysmal supraventricular tachycardia (PSVT), we evaluated the electrophysiologic effects and therapeutic efficacy of intravenous flecainide, administered in a dose of 2 mg per kg body weight in 26 patients of PSVT, studied by programmed electrical stimulation. The patients' age ranged from 18-49 years (mean: 27 +/- 8) and none had organic heart disease. The mechanism of PSVT was atrioventricular nodal reentry (AVNRT) with anterograde conduction through slow pathway and retrograde through fast pathway in 14, and atrioventricular reentry (AVRT) utilizing an accessory pathway in 12 patients. Flecainide was successful in terminating the tachycardia in all (100%) patients of AVNRT and 11 (92%) patients with AVRT. In both the types, the tachycardia was terminated by selective block in conduction through the retrograde limb of the reentry circuit. The drug also produced a complete anterograde block with abolition of preexcitation in 6 out of 8 patients with WPW syndrome. After the drug, the tachycardia was reinducible in one patient of AVNRT and 4 with AVRT. The cycle length of inducible tachycardia increased from 295 +/- 25 ms to 389 +/- 24.5 ms after flecainide (p < 0.001). There were no adverse haemodynamic effects of the drug. Our results, thus, showed that intravenous flecainide is a highly effective and safe antiarrhythmic drug for termination of PSVT mediated by atrioventricular nodal and atrioventricular reentry mechanisms without producing any adverse effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Directional atherectomy for the dilatation of bifurcation stenoses in the coronary arteries.

Although bifurcation lesions in the coronary arteries can be dilated with balloon angioplasty, directional atherectomy is emerging as the treatment of choice in patients with large arteries. In this study, we report the immediate results and acute complications of treating bifurcation lesions in the coronary arteries with directional atherectomy in 9 patients, ranging in age from 33 to 60 (mean 56.7 +/- 10.8) years. All patients had true bifurcation stenoses with luminal diameter narrowing of more than 70 percent in both the primary vessel and the side branch. The lesions involved the left anterior descending (LAD)-diagonal system in 5, left circumflex (LCx)-obtuse marginal (OM) in 2, distal right coronary artery (RCA) in 1 and bifurcation of a large first diagonal branch in one patient. Double-wire atherectomy technique was used in 4 patients, although 7 had an additional wire in the side branch during post-atherectomy balloon angioplasty. The procedure was successful in all patients (100%), with luminal diameter stenosis decreasing from 93 +/- 7.5 percent to 6 +/- 8.6 percent in the primary vessel and from 83 +/- 9.2 percent to 13 +/- 9 percent in the side branch. There were no major complications. Minor complications included non-flow limiting dissection in 4 patients, distal migration of thrombus in one, occlusion of 2 small distal branches of the diagonal in one and entwinement of the guidewires in one. In conclusion, directional atherectomy can be performed safely and successfully for dilatation of complex bifurcation lesions in the coronary arteries without any major complications using the double-wire or sequential atherectomy technique.

Adult↗

PubMedDate not supplied

Coronary stenosis associated with aneurysm: treatment with elective stenting in two patients.

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Angioplasty, Balloon, Coronary↗

PubMedDate not supplied

Ventricular tachycardia with left bundle branch block morphology in the absence of ischaemic heart disease--clinical and electrophysiological observations.

Clinical and electrophysiological features of 20 patients presenting with ventricular tachycardia (VT) of left bundle branch block (LBBB) morphology without evidence of coronary artery disease were studied. The mean age of the patients was 35.2 +/- 12 (range 15-57 years). The rate of VT varied between 140-240/min (182 +/- 80). Six (30%) patients experienced giddiness or syncope during palpitations. Structural heart disease was found in 10 (50%) of these patients, which included arrhythmogenic right ventricular dysplasia in five, submitral left ventricular (LV) aneurysm in one, anterolateral LV dyskinesis in one, dilated cardiomyopathy in one, endomyocardial fibrosis in one and nonobstructive hypertrophic cardiomyopathy in one case. Ten patients were free of structural heart disease. Electrophysiological study was done in all patients. VT with same morphology as spontaneous VT was inducible in only 14 patients. Seventeen patients were treated medically with total or partial amelioration of symptoms. In three patients, two with arrhythmogenic right ventricular dysplasia and one with structurally normal heart, who were unresponsive to drug therapy, the VT focus could be mapped in right ventricular outflow tract and successful electrical ablation was done. Thus in patients who present with VT with LBBB morphology, the heart is often structurally normal but organic disease is not uncommon, and should be carefully searched.

Adult↗

PubMedDate not supplied

Comparative evaluation of left ventricular function in sick sinus syndrome on different long-term pacing modes.

Single-chamber ventricular pacing has been implicated in the development or progression of congestive heart failure in patients with sick sinus syndrome (SSS). To define the exact role of pacing modality in causation of congestive heart failure, quantitative two-dimensional echocardiographic examination was performed in 51 consecutive patients with SSS who received an initial pacemaker from January 1979 to September 1989 and were free of any structural heart disease at the time of implant. Atrial or dual chamber pacemakers were implanted in 21 patients (Group I) and ventricular pacemakers in 30 (Group II). The two groups were matched for age, gender, paced rate, blood pressure and duration of pacing. After a mean follow-up of 64 +/- 34 months, congestive heart failure developed in one patient in group I and 3 in Group II. Patients in group II, had larger left atrium (41 +/- 5 vs 37 +/- 6 mm, p < 0.05) and left ventricular end-diastolic volume (64 +/- 18 vs 54 +/- 12 ml/m2, p < 0.01) but similar left ventricular end-systolic volume (27 +/- 12 vs 24 +/- 9 ml/m2, p = NS), ejection fraction (59 +/- 10 vs 57 +/- 8%, p = NS), left ventricular mass (84.8 +/- 31 vs 85.6 +/- 29.2 gm/m2, p = NS), meridian end-systolic wall stress (48.3 +/- 22.1 vs 49.8 +/- 25 Kdynes/cm2, p = NS) and wall stress/end-systolic volume ratio (1.27 +/- 0.94 vs 1.42 +/- 0.59, p = NS). Pacing mode does not appear to influence left ventricular systolic function in patients with SSS.

Cardiac Pacing, Artificial↗

PubMedDate not supplied

Atrial contribution to left ventricular filling in mitral stenosis: effects of balloon mitral valvuloplasty.

Doppler echocardiographic contribution of atrial systole to left ventricular filling (AC) was studied in 20 patients with mitral stenosis and compared with that obtained from 15 matched controls in a prospective study. AC in mitral stenosis as a percentage of total filling volume was 8 +/- 2.8% compared to 12.5 +/- 3.3% in control subjects (p < 0.001) and was weakly correlated to diastolic filling period (r = -0.45), mitral valve orifice resistance (r = -0.36) and heart rate (r = 0.36). An increase in mitral valve orifice area following balloon mitral valvuloplasty (0.78 +/- 0.12 to 1.72 +/- 0.4 cm2, p < 0.0001) resulted in an increase in AC to near normal values (8 +/- 2.8% to 12.5 +/- 3.8%, p < 0.001) coupled with an increase in cardiac index and a significant decrease in diastolic filling period and left atrial size. In conclusion, AC in young patients with severe mitral stenosis is decreased proportionately less than that reported in the older patients, is weakly correlated to mitral orifice resistance and normalises following a successful mitral valvuloplasty.

Adult↗