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Biomedical subjects

K K Talwar

Publications and source records attributed to K K Talwar.

At least 37 records · Page 2Linked to original sources
PubMed2000

Thrombolytic therapy for prosthetic valve thrombosis: short- and long-term results.

BACKGROUND: Thrombolytic therapy (TT) has evolved as an alternative to surgery for prosthetic valve thrombosis (PVT), but its utility in patient management is still debated and the long-term results are not available. METHODS: From 1990 through 1999, we treated 110 consecutive patients (52 men, mean age 35.4 +/- 10.8 years) of left-sided obstructive PVT (96 mitral, 14 aortic) with TT (streptokinase in 108, urokinase in 2) according to a specified protocol of prolonged infusion. Serial echo Doppler parameters were monitored in all patients to guide the duration of TT and to quantify its efficacy. Ninety of the 102 survivors of the index episode were followed up for a mean period of 31.3 +/- 27.8 months (range 1-112 months). RESULTS: Complete hemodynamic response (on cinefluoroscopy and echo Doppler criteria) was seen in 90 (81.8%) episodes, partial response in 11 (10%), and failure in 9 (8.2%). The mean duration of TT was 42.8 +/- 20.4 hours. Five of the 7 patients who were initially seen in cardiogenic shock/overt pulmonary edema died during therapy. After these patients were excluded, the rate of complete response did not differ among patients with New York Heart Association class I/II (80%), class III (86.3%), or class IV (81.5%). The response rate also did not vary with the type, position of prosthesis, duration of symptoms, or time lag since surgery. There were 21 (19.1%) embolic episodes during therapy, including 6 strokes. These were significantly more frequent in patients with atrial fibrillation (AF) (odds ratio on multivariate analysis 2.3, 95% confidence interval 1.3-3.9, P =.01). On follow-up, there were 25 recurrences of PVT, of which 20 again received TT with a complete response in 14 (70%). At 5 years the actuarial survival was 85.2% and the event-free survival was 61.5%. The presence of chronic AF was a significant predictor of recurrence of PVT (odds ratio 2.2, 95% confidence interval 1.2-3.9, P =.008). CONCLUSIONS: TT is effective in the majority of patients with PVT but is associated with a high rate of embolism, especially in patients with AF. Excluding patients with cardiogenic shock/overt pulmonary edema (in whom TT is largely ineffective), the success of TT does not vary with the New York Heart Association class, duration of symptoms, or other patient variables. The recurrence rates of PVT are high after even successful TT, especially in patients with AF.

Adolescent↗
PubMed1999

Percutaneous balloon mitral valvuloplasty using the Inoue balloon: analysis of echocardiographic and other variables related to immediate outcome.

To determine whether the mitral valve morphology influences the results of percutaneous balloon mitral valvuloplasty for mitral stenosis, two-dimensional echocardiography was performed before valvuloplasty in 126 patients (mean age 25.5+/-9.4 years) and in 30 normal controls. The 2D echocardiographic features of mitral valve leaflets: thickness, length and motion; diastolic mitral valvular excursion; chordal length; mitral annular diameter; subvalvular distance ratio; distance between mid mitral annulus to left ventricular apex, base and tip of papillary muscle and effective balloon dilating area, effective balloon dilating area/body surface area and effective balloon dilating diameter/mitral annular diameter were then correlated to the immediate post-valvuloplasty mitral valve area. For the total patients population, post-valvuloplasty valve area increased from 0.67+/-0.17 to 2.1+/-0.86 cm2 (P<0.0001), mean transmitral diastolic gradient decreased from 24.5+/-9.0 to 6.0+/-3.0 mm Hg (P<0.0001), mean left atrial pressure decreased from 29.7+/-6.2 to 12.7+/-4.8 mm Hg (P<0.0001), mean pulmonary artery pressure decreased from 44.8+/-14.2 to 25.4+/-9.5 mm Hg (P<0.0001) and cardiac index increased from 2.7+/-0.38 to 3.1+/-0.55 l/min/m2 (P<0.0001). The patients were divided into three groups on the basis of post-valvuloplasty mitral valve area. Group I had valve area <1.5 cm2, group II had valve area from 1.5 to 1.9 cm2 and group III had valve area > or =2.0 cm2. On comparison, no statistically significant difference was found in any of the echocardiographic variables in the three groups. On univariate, multivariate, multiple regression and discriminate function analysis, none of the variables were found to have significant influence on immediate result of valvuloplasty. There was no significant difference in the incidence of mitral regurgitation in any of the three groups. We conclude that the extent of mitral valvular and subvalvular deformity do not have a significant effect on the immediate outcome of mitral valvuloplasty using the Inoue balloon and it can be successfully performed in patients with severe subvalvular fibrosis. Unique balloon geometry and stepwise balloon sizing may explain these acceptable immediate results in severely deformed valves.

Adult↗
PubMed1999

Stenosis in the aorta caused by non-specific aortitis: results of treatment by percutaneous stent placement.

AIM: To evaluate the short-term results of percutaneous stent placement in treating stenosis in the aorta caused by non-specific aortitis (Takayasu's disease). METHOD: Five patients were treated by this method, all of whom had uncontrolled hypertension, haemodynamically significant stenosis in the aorta and a clinically inactive disease. Stents were placed to treat an obstructing dissection in four and recurrent stenosis in one patient. All procedures were carried out via the percutaneous transfemoral route, utilizing self-expanding stents. RESULTS: The lesion was located in the thoracic aorta in three patients and in the abdominal aorta in two patients. The stenosis decreased from 81+/-2 to 7+/-3%, the pressure gradient fell from 97+/-5 to 9+/-2 mmHg, the blood pressure improved from 200+/-3/124+/-2 to 131+/-2/81+/-2 mmHg, and the drug requirement fell from 4+/-.2 to 1.3+/-.3 (P value for all <0.001). No complication was encountered. At follow-up at 13+/-4 months, all of the patients had improved clinically. Intimal hyperplasia within the stent was seen in two patients who underwent follow-up angiograms. CONCLUSION: Percutaneous aortic stenting is useful in treating selected patients with non-specific aortitis. Further information about the long-term behaviour of intimal hyperplasia and the response of stented segments to the aging process needs to be understood before elective stenting in this young patient population can be advocated.

Adolescent↗
PubMed1998

Immunogenetic analysis of Takayasu arteritis in Indian patients.

The distribution of HLA-A, B, C and DR antigens was determined in a cohort of 104 unrelated Indian patients with Takayasu arteritis (TA) belonging to the North Indian states of Punjab, Haryana, Uttar Pradesh and Delhi. The data was compared with healthy controls belonging to the same ethnic group. In addition, polymorphism in the MHC class I chain related A (MIC A) gene was studied in a group of 25 TA patients and 40 healthy controls. The data revealed a strong association of the disease with HLA-B5 (chi2=22.5, P<1 x 10(-6), RR=3.08) as well as its two common serological subtypes, B51 (chi2=20.5) and B52 (chi2=18.5). No particular association was observed with any of the five alleles of the MIC A gene, nor any linkage disequilibrium could be established with these alleles and those of HLA-B locus in this population. The observation suggest that HLA linked genes are definitely involved in the development of Takayasu arteritis and that the disease in Indian subjects is associated with HLA-B5 and its two serological subtypes, B51 as well as B52.

Adolescent↗
PubMed1998

Septal course of the left main coronary artery from right aortic sinus and ventricular tachycardia.

A 42-year-old man with resistant ventricular tachycardia was found to have an anomalous origin of the left main coronary artery from the right aortic sinus that pursued an intramyocardial course through the ventricular septum. The tachycardia resolved after coronary artery bypass graft to otherwise normal left anterior descending and circumflex coronary arteries. Septal course of an anomalous left main coronary artery from right aortic sinus should not always be considered benign.

Adult↗
PubMed1998

Long-term outcome of intracoronary microstent implantation: lesion matched comparison with Palmaz-Schatz stent.

We performed a lesion matched comparison of AVE Microstent and Palmaz-Schatz stent implants with 6 month follow-up angiography to compare the occurrence of restenosis. Thirty-three pairs of lesions were matched for lesion location, ACC/AHA lesion type, reference diameter, lesion length, and angiographic descriptors. Age, sex, clinical profile, and indication for stenting were comparable. Quantitative coronary analysis before and after the procedure was comparable in the two groups but minimum lumen diameter (MLD) at follow-up was less with Microstent--2.01 +/- 1.01 mm than Palmaz-Schatz stent--2.43 +/- 0.96 mm (P = 0.05). Binary restenosis was present in 33% and 21% and was diffuse in 55% and 29% of the two groups, respectively. Typical angina at follow-up was more frequent with Microstent (36%) than Palmaz-Schatz stent (15%; P = 0.038). When implanted in lesions of similar complexity, Microstent yields similar post procedure angiographic results but smaller MLD at follow-up and more frequent angina than Palmaz-Schatz stent.

Adult↗
PubMed1997

Comparative evaluation of transthoracic and transesophageal echocardiography in detection of left atrial thrombus before percutaneous transvenous mitral commissurotomy. Do all patients need transesophageal examination?

We postulated that the sensitivity of transthoracic echocardiography in detection of left atrial cavity or appendage thrombi is better in south-east asian patients with rheumatic mitral stenosis. This was considering that these patients are generally younger, have lesser body weight and thinner chest walls resulting in better transthoracic echogenecity than their western counterparts. We prospectively performed transthoracic and transoesophageal echocardiography in 150 consecutive Indian patients (mean age 28.8+/-7.2 years; 78 men) being evaluated for percutaneous transvenous mitral commissurotomy. The overall sensitivity of transthoracic echocardiography was 74% (95% C.I. 59-88%). This was significantly higher than the pooled estimate from five western reports which evaluated similar patients (overall sensitivity 12%; 95% C.I. 0-25%; P<0.0001). The sensitivity rose to 83% when patients with poor echogenecity were excluded. Amongst patients with good echogenecity (81% patients) the diagnosis of left atrial thrombi was correctly made or suspected on transthoracic examination in all patients subsequently shown to have thrombi on transoesophageal echocardiography. Significant savings in cost may be safely achieved by limiting transoesophageal echocardiography to patients in whom left atrial cavity or appendage is not adequately visualized on transthoracic examination due to poor echogenecity, or in whom there are shadows suggestive but not diagnostic of thrombi.

Adolescent↗
PubMed1997

Balloon mitral valvotomy: comparison between antegrade Inoue and retrograde non-transseptal techniques.

AIMS: The results of percutaneous mitral valvotomy performed by the antegrade transseptal method using the Inoue balloon (n = 1000; group 1) and by the retrograde non-transseptal technique using a polyethylene balloon (n = 100; group 2) were compared in a retrospective, non-randomized study. METHODS AND RESULTS: Both the groups were similar with respect to baseline characteristics. The success rate was 95% in group 1 and 93% in group 2. There was a significant increase in mitral valve area estimated by Gorlin's equation (Group 1: from 0.8 +/- 0.5 to 2.1 +/- 0.8 cm2; Group 2: from 0.8 +/- 0.3 to 1.9 +/- 0.8 cm2, both P < 0.001) and by Doppler echocardiography using the pressure half-time method (Group 1: from 0.9 +/- 0.4 to 2.2 +/- 0.6 cm2; Group 2: from 0.9 +/- 0.3 to 2.0 +/- 0.7 cm2, both P < 0.001). However, the calculated immediate post-valvotomy mitral valve area was larger with the Inoue technique (2.1 +/- 0.8 vs 1.9 +/- 0.8 cm2; (P < 0.02). Results were considered optimal when the mitral valve area increased to > or = 1.5 cm2, the percentage increase was > or = 50, and mitral regurgitation was < or = 2/4. Out of the total successful procedures, optimal results were obtained in 95% patients in Group 1 and 94% in Group 2. Incidence of significant mitral regurgitation (> or = grade 3/4) was similar in two groups (Group 1: 4% vs Group 2: 5%, P = ns). A significant left to right atrial shunt (Qp/Qs > or = 1.5:1) in 2.5% and tamponade in 2% of cases occurred exclusively with the Inoue technique, while conduction disturbances, such as transient (< 24 h) left bundle branch block (28%) and complete heart block (2%) were noted with the retrograde technique (Group 2). Local complications were significantly higher in Group 2 (3% vs 0.5%, P < 0.01). The procedure time with the Inoue technique was shorter than with the retrograde (Group 1: 15 +/- 8, range 10 to 35 min; Group 2: 22 +/- 14, range 15 to 45 min, P = 0.05). Echocardiographic follow-up at 1 year showed no significant difference in mitral valve area between the two groups (Group 1 (n = 300): 1.8 +/- 0.8 vs Group 2 (n = 60): 1.9 +/- 0.9 cm2; P = 0.3). CONCLUSIONS: Balloon mitral valvotomy using the Inoue balloon and the retrograde non-transseptal technique results in significant immediate haemodynamic and symptomatic improvement. The Inoue technique achieved a larger immediate post-valvotomy mitral valve area, but the difference was not apparent at 1 year follow-up. Incidence of significant mitral regurgitation was similar with both the techniques; however, local complications occurred more frequently with the retrograde technique. Both techniques may complement each other in technically difficult cases.

Adult↗
PubMed1996

Embolization of a Wiktor stent within a stent: successful nonsurgical management.

A case of embolization of an unexpanded Wiktor stent while attempting to traverse an expanded Wiktor stent is reported. The embolized stent was subjected to longitudinal axial traction, using a balloon catheter to cause stretching and partial unraveling. This partially unraveled stent was deployed across the dissection to scaffold it. The patient had no postprocedure complications.

Aged↗
PubMed1996

Comparative study of the efficacy of metoprolol and verapamil in patients with syncope and positive head-up tilt test response.

Head-up tilt testing is a reliable diagnostic tool for patients with recurrent unexplained syncope. It has also been used to assess the drug efficacy for the treatment of patients with syncope. The objective of this study was to assess the efficacy of verapamil compared with metoprolol in a randomized crossover design for patients with syncope and a positive tilt test response. Twenty-eight patients with a positive head-up tilt test were randomized to receive either metoprolol or verapamil; the test was repeated after 7 days of therapy. Of the 15 patients initially given metoprolol, 2 (13.3%) did not respond; both were crossed over to verapamil, to which they remained unresponsive. Of the 13 patients who initially received verapamil, 8 (61%) did not respond; after crossing over to metoprolol therapy, 1 remained unresponsive. Overall, 20 of 23 patients receiving metoprolol had negative results on repeat tilt testing, whereas only 5 of 15 patients receiving verapamil had negative results (p < 0.001). In conclusion, the results of this study suggest that verapamil is considerably less efficacious than metoprolol in managing neurocardiogenic syncope.

Adolescent↗
PubMed1996

Hemodynamic predictors of early intolerance and long-term effects of propranolol in dilated cardiomyopathy.

BACKGROUND: Fifty-six patients with dilated cardiomyopathy (DCM) (aged 14-68 years) and background therapy of angiotensin-converting enzyme inhibitors, diuretics, and digoxin were given an initial challenge of propranolol in gradually increasing doses. These patients were studied noninvasively and hemodynamically and subjected to right ventricle biopsy. METHODS AND RESULTS: Forty-four patients tolerated propranolol and received the drug for 6 months; 12 patients deteriorated after starting the drug with worsening of congestive heart failure and/or hypotension. The patients who did not tolerate propranolol had higher left ventricular end-diastolic dimension (73 +/- 8 vs 66 +/- 8 mm, P < .05), and severe mitral regurgitation was more common. Hemodynamically these patients had higher heart rate, right ventricular end-diastolic pressure, mean pulmonary artery pressure, mean pulmonary artery wedge pressure, and left ventricular end-diastolic pressure (102 +/- 16 vs 89 +/- 12 beats/min, 15 +/- 7 vs 9 +/- 4, 39 +/- 16 vs 31 +/- 12, 28 +/- 8 vs 21 +/- 8, 28 +/- 8 vs 22 +/- 8 mmHg, respectively, P < .01). These patients had a significantly lower cardiac index (1.9 +/- 0.6 vs 2.5 +/- 0.6 L/min/m2, P < .01). Forty patients completed 6 months follow-up evaluation and were further subjected to repeat noninvasive and hemodynamic study. There was a significant improvement in New York Heart Association class, cardiothoracic ratio, and left ventricular end-diastolic dimension (68% vs 62%, 66 +/- 8 vs 62 +/- 7 mm, respectively, P < .01), while the ejection fraction (EF) rose from 23 to 35% (P < .001). Hemodynamically, there was a significant decrease in heart rate, right ventricular end-diastolic pressure, mean pulmonary artery pressure, mean pulmonary artery wedge pressure, and left ventricular end-diastolic pressure (91 +/- 14 vs 71 +/- 5 beats/min, 9 +/- 4 vs 5 +/- 3, 32 +/- 11 vs 22 +/- 7, 25 +/- 9 vs 17 +/- 8, 21 +/- 7 vs 14 +/- 4 mmHg, P < .05). The cardiac index rose from 2.3 +/- 0.6 to 3.2 +/- 0.7 L/min/m2 (P < .01). CONCLUSIONS: Propranolol in dilated cardiomyopathy is associated with significant intolerance. Those who tolerate propranolol seem to have long-term beneficial effects. This study is limited as it is uncontrolled and nonrandomized.

Adolescent↗
PubMed1996

Reversibility of "tachycardia induced cardiomyopathy" following the cure of idiopathic left ventricular tachycardia using radiofrequency energy.

We report a case of incessant ventricular tachycardia with right bundle branch block and left axis deviation morphology resulting in severe LV dysfunction and congestive heart failure. Radiofrequency ablation of the appropriate site in the region of posteroapical part of the LV septum resulted in the cure of the arrhythmia. On a 3-month follow-up, the LV size and function returned to normal.

Adolescent↗
PubMed1995

Balloon mitral valvotomy in patients with systemic and suprasystemic pulmonary artery pressures.

Mitral stenosis with severe pulmonary artery hypertension constitutes a high risk subset for surgical commissurotomy or valve replacement. Balloon mitral valvotomy has been proposed as a technique for treating high risk surgical patients with mitral stenosis. The efficacy of this technique in patients with severe pulmonary artery hypertension, however, has not been fully evaluated. Percutaneous transvenous mitral commissurotomy (PTMC) was performed in 450 consecutive patients. Of these, forty-five (10%) patients had systemic or suprasystemic systolic pulmonary artery pressures (110 +/- 20, range 96 to 170 mm Hg). The baseline characteristics and immediate hemodynamic results of these 45 patients with systemic/suprasystemic systolic pulmonary artery pressures (group I) were analysed and compared with those of 405 patients with subsystemic systolic pulmonary artery pressures (group II). Patients in group I were more symptomatic (New York Heart Association functional class > or = III, 96 vs. 55%, P < 0.001) and had severe subvalvular fibrosis (mitral subvalvular distance ratio [MSDR], 0.14 +/- 0.04 vs. 0.22 +/- 0.04, P < 0.01). Before PTMC, mean transmitral gradient was higher (34 +/- 8 vs. 25 +/- 4 mm Hg, P < 0.02) and mitral valve area smaller (0.5 +/- 0.3 vs. 0.9 +/- 0.4 cm2, P < 0.02) in group I patients, who also had higher pulmonary vascular resistance (16 +/- 5 vs. 9 +/- 5 U, P < 0.005). After PTMC final mean transmitral gradients (7 +/- 3 vs. 5 +/- 3 mm Hg) and mitral valve areas (1.9 +/- 0.4 vs. 2.0 +/- 0.4 cm2) were similar in both groups (P = NS). Group I patients had a greater decrease in pulmonary artery pressures (34 +/- 4 vs. 25 +/- 2%, P < 0.05) but final systolic pulmonary artery pressures (82 +/- 20 vs. 50 +/- 14 mm Hg) and pulmonary vascular resistance (12 +/- 4 vs. 6 +/- 4 U) remained significantly higher in this group (P < 0.005). Thus, in patients with severe pulmonary artery hypertension, PTMC is a safe and effective technique providing good immediate hemodynamic results.

Adult↗