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Biomedical subjects

A K Pande

Publications and source records attributed to A K Pande.

At least 19 recordsLinked to original sources
PubMed1998

The reaction of peroxynitrite with zeaxanthin.

The oxygenated carotenoids zeaxanthin and lutein, found in the macular area of the retina, may offer protection against or repair of oxidative damage associated with the degenerative diseases of aging. Since both superoxide and nitrogen monoxide, which react to form peroxynitrite, are found in the retina, we studied the reaction of peroxynitrite with zeaxanthin in liposomes. Zeaxanthin was easily incorporated into liposomes constructed from the fully saturated lipid L-alpha-dimyristoyl-phosphatidylcholine (C14:0) and from egg lecithin, and its absorbance spectrum in liposomes strongly resembles in shape and amplitude that of zeaxanthin dissolved in methanol. The reaction between peroxynitrite and zeaxanthin is first-order in both substrates. The pH profile indicates that the reaction with zeaxanthin involves peroxynitrous acid and not the conjugate anion. We hypothesize that zeaxanthin plays a major role in protection of macular tissue from oxidative damage.

Dimyristoylphosphatidylcholine↗
PubMed1996

Intravascular ultrasound for diagnosis of left main coronary artery stenosis.

Coronary angiography has many limitations for the assessment of coronary artery disease. Intracoronary ultrasound imaging may overcome some of these limitations by providing direct visualization of the luminal area. This report describes a case where intracoronary ultrasound imaging was useful for correct assessment of left main coronary artery disease which enabled avoidance of coronary artery bypass grafting in this patient. Intravascular ultrasound may be a good complement to coronary angiography in selected cases of left main coronary artery lesion.

Aged↗
PubMed1994

Coronary angioplasty for isolated non-dominant left circumflex coronary artery disease.

The study describes the clinical findings and results of coronary balloon angioplasty in 134 patients with non-dominant left circumflex coronary artery disease. The immediate angiographic success rate was 97% versus 95% for left anterior descending (P = NS), and 90% for right coronary lesions (P < 0.002). There was no hospital mortality in the circumflex group versus 1.2% in the left anterior descending (P < 0.01), and 0.4% in the right coronary artery group (P = NS). Major non-fatal cardiac complications were significantly lower in the non-dominant left circumflex coronary artery patients (no new Q-wave versus 3% in the left anterior descending, P < 0.0002, and 3% in the right coronary artery group, P < 0.01; no urgent coronary artery bypass grafting versus 2% in the left anterior descending, P < 0.001, and 1% in the right coronary artery group, P = NS). The freedom from chest pain was 63% in 112 patients (84%) with follow-up data available at 24 +/- 18 months, and mean angina class diminished to 0.7 +/- 1.3 (P < 0.001). Consumption of antianginal and other cardiac drugs was diminished during follow-up, and the number of patients on no such drugs increased from 5 to 32% (P < 0.001). Restenosis was found in 19 of 32 patients with repeat coronary angiography (59%). Repeat angioplasty was required in 22 patients during follow-up and in 4 of them (18%) it was done for new lesions. Angioplasty for isolated non-dominant left circumflex coronary artery disease yields excellent immediate and long-term results.

Angioplasty, Balloon, Coronary↗
PubMed1994

Percutaneous transluminal coronary angioplasty of left main coronary artery.

The present study is a retrospective analysis of 15 percutaneous angioplasty procedures of the left main coronary artery performed in 12 patients (8 males (66%) with a mean age of 64 +/- 12 (range 45-79) years. Twelve dilatations were elective: 8 for unstable angina, 3 for stable angina, and 1 after a recent myocardial infarction. All elective patients were protected with at least 1 patent graft to the distal left coronary artery. Emergency dilatation for evolving myocardial infarction with cardiogenic shock was done in 3 patients. The right coronary artery was dominant in 11 cases. The mean ejection fraction was 49 +/- 18% (range 21-7%). All dilatations were done through the femoral approach. Two dilatations were performed with the "kissing balloon" technique and 2 with the "kissing wire" technique. An intra-aortic balloon counterpulsation was used in 3 cases (21%). In 8 cases (53%), 1 additional coronary artery was dilated in the same session. The technical success rate was 100% and the clinical success rate 73%. For the elective dilatations, the technical success rate was 100% and the clinical success rate 92% (11/12). Four patients died during hospitalisation (27%). The mortality rate was 100% (3/3) for emergency dilatations and 8% (1/12) for elective dilatations (patient with dilatation of 3 vessels and 1 graft in the same session). After a mean follow-up of 25 +/- 28 (rang 1-88) months, the 8 patients discharged from hospital were alive.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Implications of coronary angiography in patients with suspected or known coronary artery disease.

The study analyzes the incidence of coronary lesions and their implications on the treatment offered in 500 consecutive non-selected patients (406 males (81%), age 60 +/- 10 (+/- 1 standard deviation), range 21-88 years) undergoing coronary angiography for suspicion or confirmation of coronary artery disease (excluding patients with congenital and pure valve disease, or cardiomyopathy). A history of myocardial infarction was present in 205 patients (41%). There were no prior cardiac procedures in 334 patients (67%). There was prior coronary angioplasty in 82 patients (16%), coronary artery bypass grafting in 44 (9%) and both in 4 (1%). A total of 36 patients (7%) had had prior coronary angiography only. Mean left ventricular ejection fraction was 61 +/- 12 (18-83%) and mean left ventricular end diastolic pressure was 12 +/- 6 (2-37) mmHg. Angiographically normal coronary arteries were present in 61 patients (12%) and non-significant coronary lesions in 70 patients (14%). One vessel disease was present in 169 patients (34%), two vessel disease in 97 (19%), three vessel disease in 88 (18%) and left main coronary artery disease in 15 (3%). In single vessel disease, involvement of the left anterior descending coronary artery was seen in 82 patients (49%), left circumflex coronary artery in 38 (22%) and right coronary artery in 49 (29%). In two vessel disease, involvement of the left anterior descending coronary artery and left circumflex coronary artery was present in 30 patients (31%), left anterior descending coronary artery and right coronary artery in 36 (37%) and left circumflex coronary artery and right coronary artery in 31 (32%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Success with coronary angioplasty as seen at demonstrations of procedure.

To assess the real-life results of coronary angioplasty, unidentified participants made notes on 104 cases demonstrated live at twelve international angioplasty courses in 1991. The initially planned procedure was successful in 73% with crossover to another device in 20% for an ultimate success rate of 93%. Interventions lasted an hour on average and two devices on average were used per artery tackled. Rates of success and of complication necessitating reintervention were, for balloon angioplasty (57 cases) 81% and 19%, for directional atherectomy (16 cases) 75% and 0%, for the Rotablator (12 cases) 42% and 42%, for stent implantation (10 cases) 100% and 0%, for excimer laser angioplasty (6 cases) 17% and 33%, and for Rotacs recanalisation (3 cases) 67% and 0%, respectively. The complications were occlusions (threatened, acute, or delayed) and they were usually treated by balloon angioplasty or a stent. No death or myocardial infarction was reported. The observer attending the demonstration tended to take a less favourable view of the outcome than the clinician doing the procedure and in general the results of coronary angioplasty seemed inferior to those reported in journals. Interventions done before an audience will be unusually stressful but this will be outweighed by the fact that difficult cases with a low probability of success are rarely tackled during live courses. This survey suggests that conventional balloon angioplasty, complemented by stent implantation in selected cases, is the treatment of choice.

Adult↗
PubMed1992

Coronary and left ventricular pacing as standby in invasive cardiology.

Coronary pacing using as unipolar negative electrode a guidewire placed in a coronary branch was tested in 349 sites of 300 consecutive patients undergoing coronary angioplasty. It was possible for 339 sites (97%). The threshold currents ranged from 1 to 15 (mean +/- standard deviation 3.4 +/- 2.4) mA. Side effects were seen in 13 patients (4%): 6 (2%) had transient coronary spasm, 4 (1%) had diaphragmatic stimulation, and 3 (1%) had stinging pain at the skin electrode. Of the 10 cases with pacing failure, left ventricular pacing was successfully tested in 5 by introducing the coronary wire or another wire into the left ventricle. It yielded a threshold of 2-8 (3.2 +/- 2.7) mA. Therapeutic pacing for significant bradycardia was required in 7 patients (2%). It was successful in all. Coronary or left ventricular pacing appears to be a simple and reliable temporary measure. When there is no wire in the coronary artery or for diagnostic catheterization, left ventricular pacing can be done using the same setup and any type of guidewire.

Angioplasty, Balloon, Coronary↗
PubMed1992

Aortic dissection as complication of percutaneous transluminal coronary angioplasty.

We report two cases of aortic dissection during coronary angioplasty with a disparate evolution that was due to the different location of the entry port of the dissection. Aortic dissection occurring during coronary angioplasty may be self-limiting, but it may also be life-threatening and may call for urgent surgical repair.

Aortic Dissection↗
PubMed1992

Intracoronary electrocardiogram during coronary angioplasty.

This prospective study examines the data derived from the intracoronary electrocardiogram (ECG) (derived from the coronary guide wire) compared with that from four standard surface leads (I, II, III, and V2) in documenting myocardial ischemia during coronary angioplasty. Intracoronary and surface ECGs were simultaneously recorded in 300 consecutive patients (mean age 59 +/- 10; range 33 to 80 years; 246 males [82%] during coronary angioplasty in 368 lesions (167 left anterior descending [46%], 85 left circumflex [23%], 107 right coronary arteries [29%], and nine bypass grafts [2%]), before balloon inflation, at 1 minute of inflation, and at the end of the procedure. ST segment changes (greater than 0.1 mV) were observed in the intracoronary ECG in 306 lesions (83%) (151 left anterior descending [88%], 75 left circumflex [89%], and 80 right coronary arteries [73%]) versus in 245 lesions (67%) in the surface ECG (126 left anterior descending [73%], 43 left circumflex [47%], and 76 right coronary arteries [70%]; [p less than 0.0001]). The mean ST segment shift was 0.5 +/- 0.4 mV in intracoronary and 0.1 +/- 0.2 mV in standard leads (p less than 0.0001). ST elevation was seen in 97% of cases with intracoronary ECG changes versus in 83% with surface ECG changes. The remainder had ST depression. A total of 48 lesions (13%) did not produce ECG changes and 62 (16%) had silent ischemia. In 75 lesions (21%), ECG changes were seen only in the intracoronary ECG, compared with 14 lesions (4%) with changes only in the surface ECG (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1992

Magnum/Magnarail versus conventional systems for recanalization of chronic total coronary occlusions: a randomized comparison.

The Magnum/Magnarail system consists of "over-the-wire" balloon catheters and a 0.021 inch (0.53 mm) guide wire with a 1 mm olive-shaped tip. To compare it to conventional systems, 100 consecutive unselected patients with chronic total coronary occlusions were randomly assigned to one of two groups. If the balloon could not be placed within 20 minutes of fluoroscopy time with the allocated system, a crossover to the other system was imposed. The Magnum group comprised 50 patients and 52 occlusions, and the conventional group included 50 patients and 51 occlusions. There were no significant differences with regard to the length of the occlusions (Magnum 1.4 +/- 1.3 mm, conventional 1.6 +/- 1.7 mm) or the duration (Magnum 1.4 +/- 1.9 months, conventional 1.4 +/- 1.8 months). The primary success rate before crossover with the Magnum/Magnarail system was 67% versus 45% with conventional systems (p less than 0.05). The Magnum/Magnarail system as a second tool after crossover was successful in 11 of 28 patients (39%) versus 2 of 16 patient (12%) in whom success was achieved with a conventional system as a second tool (p less than 0.05). An increase in the creatine kinase level (more than twice normal) was seen in one patient (2%) in the Magnum/Magnarail group and none in the conventional group. Q wave infarctions were not seen. There was one in-hospital death (2%) in the conventional group. There were no significant differences with regard to the number of guiding and balloon catheters or fluoroscopy time. The Magnum/Magnarail system proved superior to conventional systems for balloon recanalization of chronic total coronary occlusions in terms of higher success rates.

Aged↗