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Biomedical subjects

U Kaul

Publications and source records attributed to U Kaul.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Influence of angiographic morphology on the acute and longer-term outcome of percutaneous transluminal angioplasty in patients with aortic stenosis due to nonspecific aortitis.

PURPOSE: We studied the relationship of initial angiographic morphology in patients with aortic stenosis due to nonspecific aortitis and its relationship to immediate and later outcome following percutaneous transluminal angioplasty (PTA). METHODS: Correlation was performed in 10 successive patients by retrospective analysis. All had clinically inactive nonspecific aortitis and hemodynamically significant aortic stenosis resulting in hypertension or lower limb claudication. Five patients had discrete concentric stenosis; the other five had eccentric stenosis with diseased aortic segments adjacent to the stenosis. RESULTS: The five patients with concentric stenosis (Group I) had primarily successful and uncomplicated PTA with sustained improvement. The five patients (Group II) with eccentric stenosis had initial success in three patients and two initial treatment failures with one patient showing late improvement. Four of these patients developed large intimal flaps. One of these had an aneurysm during follow-up. Follow-up angiograms in five patients showed remodelling with further angiographic and clinical improvement. CONCLUSION: Eccentricity of the stenosis and diffuse aortic disease correlate unfavorably with immediate outcome of PTA but late improvement may still be seen.

Adolescent↗
PubMedDate not supplied

Blocking of the hepatic vein outflow by neointima covering a wallstent across a membranous stenosis of the inferior vena cava.

A 31-year-old man presented with idiopathic membranous obstruction of the suprahepatic inferior vena cava (IVC) and was treated by balloon dilation and placement of a Wallstent. The patient improved markedly. However, he developed obstruction of the hepatic vein outflow secondary to neointima formation over the stent that covered the hepatic vein ostia. The patient died of liver failure and septicemia. We believe that this is the first report of such a serious complication.

Adult↗
PubMedDate not supplied

Coronary stent thrombosis: time course and clinical outcome.

The current clinical practice of stent implantation has changed over the last few years. We analysed the incidence and time course of stent thrombosis in patients undergoing successful coronary angioplasty and stenting over the last three years. All the patients were treated with aspirin and ticlopidine. A total of 13 patients experienced stent thrombosis. The mean age was 52+/-12 years; 12 were smokers and 10 had a recent history of myocardial infarction. None of these patients had received abciximab. The median time from stent implantation to stent thrombosis was 10 hours, with all the stent occlusions occurring within 18 hours of stent implantation procedure. All the patients underwent a repeat intervention at a median time of 30 minutes after the clinical suspicion of stent occlusion. On follow-up of 1 to 24 months, three patients developed reocclusion. In the present era of coronary angioplasty and stenting, when interventional procedures are not pre-planned and patients are treated with aspirin and ticlopidine or clopidogrel at the time of stent implantation, the incidence of stent thrombosis is low; it is seen mainly in patients with recent myocardial infarction, majority of them being smokers, and occurs within 18 hours in all the patients.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Recording of double atrial potentials as a marker for isthmus block during ablation of atrial flutter.

Radiofrequency ablation is an established method for treatment of type I atrial flutter. The assessment of creation of complete bidirectional isthmus block following linear ablation of the isthmus is an integral part of ablation procedure. Conventionally, bidirectional isthmus block is tested by pacing on either side of ablation line and looking for reversal of activation sequence in the right atrium. We looked at the feasibility of recording double potentials, separated by an isoelectric interval along the ablation line as an alternative method to demonstrate bidirectional isthmus block. An attempt was made to record the double potentials following linear ablation of the cavotricuspid isthmus. Following ablation, bidirectional isthmus block was also tested by pacing from the coronary sinus os and the low-lateral right atrium. We could demonstrate double potentials in 9 of the 11 patients in whom we attempted to record them following linear ablation of flutter. The presence of bidirectional block by pacing from coronary sinus os and low lateral right atrium could be demonstrated in 10 (91%) patients. Thus, double atrial potentials, separated by an isoelectric interval can be demonstrated following ablation of atrial flutter. Double potentials, if demonstrable on coronary sinus os and low lateral right atrium pacing, could serve as an alternative marker of isthmus block.

Action Potentials↗
PubMedDate not supplied

Coronary stent implantation without lesion predilatation (direct stenting): our experience with this evolving technique.

BACKGROUND: Until recently, conventional intracoronary stent deployment required predilatation of the lesion with a balloon. However, "direct stenting" of the lesion without predilatation offers certain theoretical and practical advantages. We assessed the safety and feasibility of direct stenting in a select group of patients who were likely to benefit most from these advantages, namely, those with acute coronary syndromes. saphenous vein graft lesions, associated renal or left ventricular dysfunction and those requiring multivessel intervention. METHODS AND RESULTS: After direct stenting, intravascular ultrasound was used to assess the adequacy of stent expansion in 51 patients. One hundred and twenty patients with a total of 125 lesions (83.3% males, average age 54.6+/-12.4 years) were enrolled for direct stenting. Of these, 90% of patients had presented with acute coronary syndromes, 21.6% of patients had associated moderate-to-severe left ventricular systolic dysfunction, 6.7% of patients had associated renal dysfunction and 30.8% of patients required multivessel intervention. Angiographically visible thrombus was present in 35.2% of patients. The mean reference diameter of the lesion was 3.18+/-0.32 mm and mean percentage diameter stenosis was 76.4+/-11.2%. Almost all varieties of stents were used (8.8% bare and 91.2% mounted). Procedural success was achieved in 98.3% of patients (98.4% of lesions). In two cases, the lesion had to be predilated prior to stenting. On angiography, the need for postdilatation of the stent was apparent in 29 (23.6%) lesions. In contrast, on intravascular ultrasound evaluation done in 51 lesions after stent deployment, the need for postdilatation to optimize stent expansion was seen in 43 (84.3%) lesions. There was one instance of acute stent thrombosis and two instances of slow-flow phenomenon. There were no deaths, myocardial infarction or need for urgent bypass surgery. CONCLUSIONS: We conclude that direct stenting is feasible and safe in selected groups of patients. Optimization of stent expansion after direct stenting may often require aggressive postdilatation.

Coronary Disease↗
PubMedDate not supplied

High-risk coronary angioplasty using percutaneous cardiopulmonary bypass support.

BACKGROUND: Balloon angioplasty has a high success rate but results in abrupt closure of the vessel in 2% to 6% of patients. This can lead to haemodynamic collapse and death, particularly if the patient has poor left ventricular function. In the event of abrupt closure of the coronary vessels, such patients may not survive long enough to undergo emergency bypass surgery. The prophylactic use of cardiopulmonary bypass to support patients at high-risk for angioplasty has been reported recently. We describe our initial experience with this technique. METHODS: Eighteen high-risk patients with severe angina were subjected to balloon angioplasty after instituting percutaneous cardiopulmonary bypass support to enhance the safety of high-risk elective coronary angioplasty. All patients had a low ejection fraction, a large amount of viable myocardium perfused by the targeted artery or both (left ventricular ejection fraction < 25% in 13 patients). Triple-vessel disease was present in all of them. Angioplasty of the only remaining vessel was done in 12 patients, 2 vessels in 5 patients and a sequential graft in 1 patient. Bypass flow ranged from 2.8 to 4.5 litres and was discontinued after a mean of 35 minutes. Haemostasis was achieved by external clamp compression in 16 patients. RESULTS: The angioplasty was successfully performed in all the patients and was well tolerated. During the bypass period, the pulmonary artery diastolic pressure ranged from 0 to 8 mmHg. There was no hospital death. Two patients required surgical exploration of the femoral artery puncture site--one because of poor distal perfusion and the other for continued bleeding. During the follow up period of 1 to 10 months, 11 patients were free of angina and 1 had died. CONCLUSION: Our experience confirms that percutaneous bypass support in selected patients undergoing high-risk coronary angioplasty is safe and effective.

Adult↗
PubMedDate not supplied

Angioplasty of total coronary occlusions using combination of intracoronary Probing Catheter and balloon on wire Probe.

We describe our experience with a technique for PTCA of total coronary occlusions using the ultra low profile balloon on wire Probe. An intracoronary Probing Catheter was used to facilitate crossing the stenosis with a guide wire. This was followed by exchanging the guide wire for the Probe into the obstruction for balloon dilatation. This technique was used in 22 consecutive patients undergoing PTCA for chronic total occlusion. The total obstruction could be crossed by guide wire (0.014 flex or 0.016 standard) passed through Probing Catheter in 19 patients (86%). The obstruction could be successfully dilated by the Probe, delivered through the probing catheter, in 17 of these patients. Of the remaining 2 patients, one could be dilated by sequential dilatation using over the wire low profile balloon system and the other one by dilatation with the Probe, respectively. The Probing Catheter technique offers a new method to apply balloon on wire technology to the dilatation of chronic total coronary occlusions with very promising results.

Adult↗
PubMedDate not supplied

Congenital complete heart block in structurally normal heart--a study of 44 cases.

Data of 44 patients with congenital complete heart block and structurally normal heart have been analysed. Thirty one patients were asymptomatic (group I) and 13 patients had symptoms of low cerebral perfusion like syncope, near syncope or convulsions (group II). A ventricular rate on surface ECG was found to be significantly lower in the symptomatic group (56.7 +/- 13.2 beats per minute, bpm, in group I and 46.5 +/- 6.0 bpm in group II). Similarly wide QRS escape rhythm of greater than 0.10 seconds was more often seen in group II (2/13) as compared to group I (2/31) though the difference did not reach statistical significance. Presence of pauses of more than 3.0 seconds on ambulatory ECG monitoring were infrequent in both the groups (group I 1/7, group II 2/7), however more often seen in group II. Electrophysiological studies carried out in 11 patients were not helpful in differentiating the two groups and all the patients including two with a wide QRS escape rhythm on surface ECG showed suprahisian level of block. The corrected junctional recovery time in two groups did not show any statistical difference. A persistently slow ventricular rate of less than 50 bpm during waking hours, wide QRS escape rhythm and pauses of greater than 3 seconds on ambulatory monitoring are suggestive of high risk to the patient and may justify implantation of permanent pacemaker even in asymptomatic patients.

Adolescent↗