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Biomedical subjects

U Kaul

Publications and source records attributed to U Kaul.

195 records · Page 11Linked to original sources
PubMedDate not supplied

Retrograde non-transseptal balloon mitral valvuloplasty--an initial experience.

Eleven patients with symptomatic isolated non-calcific mitral stenosis were treated with retrograde nontransseptal balloon mitral valvuloplasty. This new technique utilizes a specifically designed steerable catheter to enter the left atrium retrogradely via the left ventricle thus avoiding transseptal puncture, an essential step in other methods of balloon mitral valvuloplasty. Technical success was obtained in ten (91%) patients. Mitral valve area increased from 0.8 +/- 0.2 to 1.8 +/- 0.4 cm2 and the transmitral gradient decreased from 23.9 +/- 7.7 to 8.2 +/- 2.8 mmHg. There were no major complications such as cardiac perforation, embolic events, cardiac tamponade or severe mitral regurgitation. This early experience, the first outside Greece (centre of origin) indicates that retrograde nontransseptal balloon mitral valvuloplasty is a simple, effective and safe technique with results comparable with other techniques of mitral balloon dilatation which require transseptal catheterisation. Further experience involving multicenteric trials, is required to determine the overall efficacy of this technique for percutaneous balloon mitral valvuloplasty.

Adolescent↗
PubMedDate not supplied

Enalapril for prevention of restenosis after coronary angioplasty.

We have evaluated the effect of enalapril in the prevention of restenosis after percutaneous transluminal coronary angioplasty by a randomized trial conducted on 95 patients. The treatment group (n = 46) received enalapril 10 mg/day besides aspirin with calcium blockers, beginning 24 hours before coronary angioplasty. The conventional medical treatment group (n = 49) received only aspirin and calcium blockers. Enrollment required the presence of angina pectoris and successful dilatation of all significant coronary narrowings. All patients were followed up for at least 6 months. Restenosis was identified by symptoms and exercise testing and confirmed by angiography. The incidence of angiographic restenosis was 34% in the enalapril group and 31% in the conventional treatment group. Long term angiotensin converting enzyme inhibition with enalapril in a dose of 10 mg per day does not prevent restenosis after coronary angioplasty.

Adult↗
PubMedDate not supplied

Radiofrequency ablation of idiopathic ventricular tachycardia.

Eleven patients (9 male, 2 female) with ventricular tachycardia (VT) and structurally normal heart underwent radiofrequency (RF) ablation of VT focus. The detailed electrophysiological mapping localized the VT focus in the left ventricular (LV) apicoseptal region in 5, LV posteroseptal region in 2, right ventricular (RV) outflow tract in 2 and RV midseptal and inflow regions in one patient each. The technique of endocardial activation mapping during VT, pacemapping and the presence of His-Purkinje potential (for LV focus) were used to identify the precise site of delivery of RF energy. The procedure was successful in 9 patients. There was no complication. The mean fluoroscopic time was 45 +/- 21 (range 20-120) minutes. RF ablation is effective and may be considered as therapy of choice for patients with ventricular tachycardia and normal heart.

Adolescent↗
PubMedDate not supplied

Ischaemic preconditioning: an intracoronary electrocardiographic study.

Brief episodes of myocardial ischaemia may enhance the tolerance to subsequent ischaemic episodes. This phenomenon has been called ischaemic preconditioning. Intracoronary electrocardiograms (ECG) were obtained during coronary angioplasty in 15 patients (13 males, 2 females; age 49 +/- 12 years) by attaching the external end of the balloon angioplasty guide wire to the V1 lead on the surface electrocardiogram. Surface leads I, II and III and intracoronary ECG were recorded at baseline and during balloon occlusion. The pattern of ST segment change during the first and subsequent inflation were compared. A significant reduction in ST segment deviation was observed in intracoronary ECG between the first and second inflation (10 +/- 1 vs 5 +/- 3 mm, p < 0.05). However, surface ECG showed no significant difference in ST segment deviation between the two inflations (3 +/- 1 vs 2 +/- 1 mm, p = NS). Thus, intracoronary ECG detects acute ischaemia more readily as compared to the routinely monitored surface ECG. A significant reduction noted in ST segment deviation during the second inflation suggests the phenomenon of ischaemic preconditioning in humans.

Adult↗
PubMedDate not supplied

Changes in circulatory biogenic amines during head-up tilt testing in neurocardiogenic syncope.

The pathogenesis of neurocardiogenic syncope is not completely understood. To examine the possible role of biogenic amines in patients with neurocardiogenic syncope, 18 consecutive patients (age 30 +/- 13 years, 15 males, 3 females) of unexplained syncope were subjected to Head-Up Tilt Testing (HUTT). Blood was sampled by an indwelling cannula at baseline, end of tilt test (or at syncope) and 1 min after returning to the supine position. Biogenic amines, epinephrine (E), norepinephrine (NE), serotonin (5-HT) and their metabolites, homovanillic acid (HVA) and 5-hydroxy indole acetic acid (5-HIAA), were measured in the serum after serial organic phase extraction by high-performance liquid chromatography (HPLC) using ultraviolet detection at a wavelength of 280 nm. Twelve patients were found to be HUTT negative while 6 patients were HUTT positive. Baseline E, NE and 5-HT levels were significantly greater in the HUTT positive patients [E 510 +/- 154 versus 302 +/- 96 pg/ml (p < 0.01), NE 253 +/- 99 versus 159 +/- 62 pg/ml (p < 0.05), 5-HT 174 +/- 32 versus 118 +/- 22 pg/ml (p < 0.01)]. E and HVA levels at the end of the test were significantly higher in HUTT positive patients [E 788 +/- 268 versus 465 +/- 119 pg/ml (p < 0.01), HVA 308 +/- 91 versus 112 +/- 12 pg/ml (p < 0.001)]. A significantly greater rise of E from the baseline was observed in HUTT positive patients (510 +/- 154 versus 112 +/- 12 pg/ml (p < 0.01)]. The increase in the levels of E and HVA both at baseline and after the tilt test, without a corresponding rise in NE levels indicates enhanced activity of the adrenomedullary axis which is not paralleled by NE release from sympathetic nerve endings in patients of neurocardiogenic syncope.

Adolescent↗
PubMedDate not supplied

In-hospital results of radiofrequency ablation of supraventricular tachycardia.

Two hundred and one consecutive patients with symptomatic paroxysmal supraventricular tachycardia (PSVT) underwent a diagnostic electrophysiological test and catheter ablation with radiofrequency (RF) current. In 102 (51%) patients, the mechanism of PSVT was found to be atrioventricular nodal reentry (AVNRT, typical in 101, atypical in 1). Atrioventricular reentrant tachycardia (AVRT) involving accessory pathway was present in 94 (47%) and ectopic atrial tachycardia in 5 patients. A successful outcome was achieved in 100 of 102 patients (98%) with AVNRT and in 85 of 94 patients (90%) with AVRT. The anatomical approach was used for ablation in patients with AVNRT. The focus was ablated in 4 patients with ectopic atrial tachycardia whereas it was modified in the remaining one patient. Procedure-related complications occurred in 4 patients (2 AVNRT, 2 AVRT). One patient each developed haemothorax, pericardial effusion, mitral valve endocarditis and high-grade AV block requiring permanent pacemaker implantation. The electrode and ablation catheters were repeatedly used after ethylene oxide sterilisation to reduce the cost of the procedure. RF ablation is an effective, safe and curative modality of treatment for patients with symptomatic PSVT due to AVNRT and AVRT. The experience with this modality in patients with ectopic atrial tachycardia is limited.

Adolescent↗
PubMedDate not supplied

Analysis of local electrograms at successful and unsuccessful sites for slow pathway ablation of atrioventricular nodal reentrant tachycardia.

Anatomic and electrogram approaches have been described for ablation of slow pathway in patients with atrioventricular nodal tachycardia. The purpose of this study was to identify parameters to predict successful slow pathway ablation using the anatomic approach. Local electrograms at successful and unsuccessful sites were compared in 36 patients undergoing slow pathway ablation using anatomic approach. A total of 208 local electrograms were studied. Fragmented atrial electrogram was seen in 24/36 (67%) of successful and in 46/172 (26%) of unsuccessful sites (p < 0.001). The sensitivity, specificity and positive and negative predictive values of fragmented atrial electrogram were 67, 73, 34 and 91 percent respectively. A slow pathway potential was noted in three of successful sites. There was no difference in the atrial to ventricular amplitude ratio in these sites. In conclusion, fragmentation of atrial electrogram and presence of possible slow pathway potential are seen more often at successful than at unsuccessful sites. In our opinion, while using an anatomic approach for slow pathway ablation, an analysis of local electrogram may help in identifying the proper site and avoiding unnecessary radiofrequency energy delivery.

Adult↗
PubMedDate not supplied

Outcomes of primary stenting for acute myocardial infarction.

Primary coronary stenting is being increasingly used in patients undergoing primary coronary angioplasty for acute myocardial infarction. In this prospective study we analysed our experience of direct angioplasty in 76 patients with acute myocardial infarction of whom 65 received intracoronary stents using high pressure deployment (> or = 12 atm) with adjunctive aspirin and ticlopidine therapy but without coumadin. All patients underwent pre-discharge angiography. Stent implantation was successful in all patients. Stent thrombosis was not seen in any patient. However, TIMI grade 3 flow was obtained in only 58 (89.2%) patients with evidence of slow-flow present in the remaining seven patients. Pre-discharge angiograms showed no-stent thrombosis but five out of the seven (71%) patients with slow-flow phenomenon persisted to have slow-flow. These patients had lower left ventricular ejection fraction as compared to patients with TIMI 3 flow at pre-discharge angiography (27.5 +/- 10.2% vs 42.1 +/- 15.2%; p < 0.001) and a high mortality (2 out of 7) within 30 days. Primary stenting is safe and feasible in the majority of patients with good short-term outcome. But persistent slow-flow phenomenon with adverse clinical outcome is seen in a small but significant number of patients.

Adult↗