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Biomedical subjects

V Dev

Publications and source records attributed to V Dev.

At least 55 records · Page 3Linked to original sources
PubMed1991

Probe angioplasty through an intracoronary probing catheter in lesions which are difficult to cross.

The clinical records of the first 17 consecutive patients (20 lesions) in whom percutaneous transluminal coronary angioplasty was done using the ultra-low profile "balloon-on-wire probe" passed through an intracoronary probing catheter were reviewed. All patients had high-grade "difficult" lesions. In 15 lesions (12 patients) other balloon systems (over-the-wire low profile balloons (n = 9), and balloon-on-wire used alone, (n = 6)) had failed to cross the lesion. Acute ischemia due to complete occlusion at the site of the lesion during attempts to cross was seen in 3 of these patients. The intracoronary probing catheter was used to deliver the probe across the lesion in all these cases. Successful dilatation was achieved in 14 lesions (93%). In 5 lesions (5 patients) this combination was used as the initial strategy. Three of these had chronic total occlusions. Successful dilatation was achieved in 3 lesions (60%) using this combination and in 1 lesion over-the-wire balloon finally succeeded. There was 1 failure. The intracoronary probing catheter in combination with probe balloon wire offers a promising method to increase the success rate in patients with high grade "difficult" lesions. This combination is especially useful in situations where other balloon systems fail to cross the lesion.

Angioplasty, Balloon, Coronary↗
PubMed1991

The morphology of coronary arterial dissection occurring subsequent to angioplasty and its influence on acute complications.

We reviewed the records of 402 patients undergoing percutaneous transluminal coronary angioplasty to identify factors predicting an ischemic event with arterial disruption during an otherwise uncomplicated angioplasty. Major dissection of the coronary arteries without immediate occlusion was found in 25 patients, who exhibited 28 dissected lesions. Dissections were classified into 2 types: those producing a continuous extraluminal and parallel filling tract, and those with a continuous parallel filling tract extending into and compromising the lumen. Ischemic complications (defined as myocardial infarction, the need for repeat angioplasty, or coronary arterial bypass surgery) occurred in 6 patients (24%) within 24 hours of the completion of the procedure. The remaining 19 patients had an uncomplicated hospital course. Acute ischemic complications following dissection correlated with the percentage of luminal compromise 50 +/- 0% in those with complications as opposed to 17 +/- 21% in those without: P less than 0.001) and the development of dissection producing a filling tract which compromised at least half the lumen (100% in those with complications versus 9.1% in those without: P less than 0.001). There was a trend towards an increase in ischemic complications in patients with proximal and eccentric lesions. We conclude that patients who develop dissections which produce significant luminal compromise after an otherwise uncomplicated angioplasty are at a high risk of developing an acute ischemic complication within 24 hours of the procedure.

Acute Disease↗
PubMed1991

Value of exercise vectorcardiography and exercise radionuclide ventriculography in identification of coronary arterial disease in patients with left bundle branch block.

Twelve patients (8 male and 4 female, age ranged 39-60 years) with suspected coronary arterial disease with left bundle branch block were evaluated for ischemia by simultaneous exercise vectorcardiography and radionuclide-ventriculography. Selective coronary angiography revealed normal coronary arteries in 5 and significant coronary arterial disease in 7 patients. Radionuclide ventriculography revealed no significant difference in resting left ventricular ejection fraction in patients with normal coronary arteries (44.0 +/- 13.9%) and coronary arterial disease (45.7 +/- 11.9%). Exercise radionuclide ventriculography showed positive response suggestive of ischemia in 11 patients (11/12), including all 5 with normal coronary arteries and 6/7 with coronary arterial disease. The magnitude of spatial 'R' maximum cardiac vector in both groups at rest (normal coronary arteries: 1.61 +/- 0.22 mV, coronary arterial disease: 1.63 +/- 0.35 mV) did not show any significant difference. On exercise, the magnitude of spatial 'R' maximum cardiac vector uniformly increased in patients with normal coronary arteries (1.61 +/- 0.22 to 1.75 +/- 0.25 mV, P less than 0.01) and decreased in 6 and remained unchanged in 1 patient with coronary arterial disease (1.63 +/- 0.35 to 1.34 +/- 0.46 mV, P less than 0.01). There was no change in rotational characteristics of QRS and T loops at end exercise in either group. Our preliminary observations indicate that exercise induced alteration of the magnitude of the maximal spatial 'R' cardiac vector appears to be an useful parameter to diagnose underlying coronary arterial disease in patients with left bundle branch block. Having a high false positive response, exercise radionuclide ventriculography appears to be of limited value in these patients.

Adult↗
PubMed1991

Persistent atrial standstill--clinical, electrophysiological, and morphological study.

Persistent atrial standstill (PAS) is a rare disorder characterized by absence of atrial activity on the surface and intracavity electrograms, absence of atrial mechanical activity, and inability to electrically stimulate the atria. Four patients (ages 18-60 years) with PAS were evaluated. One of these (no. 3) only had right atrial (RA) standstill, whereas left atrium (LA) showed spontaneous activity and could be stimulated electrically. As RA biopsy is not possible, right ventricular (RV) endomyocardial biopsy (EMB) was obtained to identify possible atrial pathology that revealed inflammatory myocarditis, 2; amyloidosis, 1; and myocardial hypertrophy with fibrosis, 1. Three patients were given permanent pacemakers. One of these with amyloidosis died suddenly. One is lost to follow-up. The others cases are persisting with PAS.

Adolescent↗
PubMed1991

Silent myocardial ischemia after percutaneous transluminal coronary angioplasty and its prognostic significance.

A cohort of 175 patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) were subjected to a treadmill exercise test to determine the prognostic significance of silent and symptomatic myocardial ischemia during the follow-up (average 11.7 months). The cardiac events during the follow-up were defined as cardiac death, nonfatal myocardial infarction, class III angina, and need for repeat angioplasty or coronary artery bypass surgery. During exercise, 39 patients (22%) had abnormal exercise-induced ST depression without chest pain (Group I). A group of 22 patients (13%) had both exercise-induced chest pain and ST-segment depression (Group II), and 114 patients (65%) had normal exercise test and no chest pain (Group III). The groups were similar in sex distribution, history of previous myocardial infarction, distribution of vessel disease, and presence of left ventricular dysfunction. Group III included more patients with complete revascularization. Follow-up data revealed that cardiac event rates in Groups I and II were significantly higher than in Group III (41%, 41%, vs. 16%) (p less than 0.01). The event rates in Groups I and II with multivessel angioplasty also were significantly higher than in Group III (58%, 61%, vs. 21%) (p less than 0.01). Exercise-induced silent myocardial ischemia is frequently seen early after successful PTCA and is more prevalent in patients undergoing multivessel angioplasty and incomplete revascularization. Both silent and symptomatic ischemia early after PTCA are predictors of an unfavorable prognosis.

Angioplasty, Balloon, Coronary↗
PubMed1990

Doppler assessment of interventricular pressure gradient across isolated ventricular septal defect.

Continuous wave Doppler ultrasound was used to estimate the pressure gradient between the right and left ventricle for assessment of pulmonary arterial systolic pressure in 30 patients with isolated ventricular septal defect and for subsequent comparison with similar data obtained on cardiac catheterization. The age of the patients ranged from 8 months to 45 years (6.8 +/- 8.6 years). No patient had right or left ventricular outflow tract obstruction. Doppler measurements were done within 24 h of cardiac catheterization. Pressure gradient across ventricular septal defect on cardiac catheterization ranged from 7 to 95 mmHg (48 +/- 24 mmHg) and that on Doppler assessment ranged from 8 to 78 mmHg (42 +/- 20 mmHg). Doppler measurements of interventricular pressure gradient correlated well with those obtained on cardiac catheterization (r = 0.90, p less than 0.001). Correlation was better in patients with pressure gradient across ventricular septal defect less than 75 mmHg (r = 0.96). Correlation was poor in three of five patients with very small ventricular septal defects (interventricular pressure gradient greater than 75 mmHg) because the jet used was not ideal. Thus continuous wave Doppler ultrasound is an accurate noninvasive means of measuring pressure gradient across ventricular septal defect, which is a useful parameter for assessment of pulmonary artery systolic pressure in patients with isolated ventricular septal defect without right and left ventricular outflow tract obstruction.

Adolescent↗
PubMed1990

Echo-Doppler assessment of cardiac status in conjoined (thoraco-omphalopagus) twins.

Cardiac status was assessed noninvasively in a case of thoraco-omphalopagus conjoined twins by two-dimensional and Doppler echocardiography which showed completely separate hearts and major arteries and veins. The twins were successfully separated surgically, without preoperative invasive cardiac investigation. Echocardiography can provide an accurate assessment of cardiac status in conjoined twins and may obviate the need for cardiac catheterization.

Echocardiography↗
PubMed1990

Initial experience with percutaneous transluminal angioplasty in the management of Takayasu's arteritis.

We have performed percutaneous transluminal angioplasty (PTA) for 15 arterial stenoses in 11 patients with Takayasu's arteritis. The lesions included tight, proximally located renal artery stenosis (12 stenoses; nine patients), localized abdominal aortic stenosis (two patients) and occluded left common iliac artery (one patient). Clinically successful dilatation was achieved in seven patients (10 stenoses) with renal artery stenosis, in both the patients with abdominal aortic stenosis and in the only patient with an occluded left common iliac artery. No complications related to the procedure were encountered. The follow-up period (n = 7) ranged between 1 and 16 months, mean follow-up period after renal angioplasty was 5 months and after abdominal aortic angioplasty was 12.5 months. Initial success has been maintained in both the patients with abdominal aortic stenoses and in four out of five patients with renal artery stenosis. Percutaneous transluminal angioplasty offers an attractive alternative for the management of stenosing lesions in Takayasu's arteritis with good short term results.

Adolescent↗
PubMed1989

Doppler echocardiographic assessment of transmitral gradients and mitral valve area before and after mitral valve balloon dilatation.

This is a comparative study of 60 sets of observations of mitral valve end-diastolic gradient, mean diastolic gradient, and mitral valve area obtained by Doppler echocardiography and cardiac catheterization. The studies were performed in 28 patients, 16 of whom underwent mitral valve balloon valvuloplasty. These 16 patients had studies performed before, immediately after valvuloplasty, and one week later. Thus 28 studies were performed before or without valvuloplasty (Group I) and 32 after valvuloplasty (Group II). The time interval between Doppler echocardiography and cardiac catheterization was less than 24 hours in 44 studies and 24 to 72 hours in 16 studies. In Doppler echocardiography the gradients were obtained by simplified Bernoulli's equation and the mitral valve area by pressure half-time method. There was excellent correlation between end-diastolic gradients (r = 0.96, p less than 0.001) and mean diastolic gradients (r = 0.92, p less than 0.001) measured by the two techniques. A statistically significant correlation also existed in the mitral valve area values (r = 0.53, p less than 0.005). On separate analysis Group I showed excellent correlation for all three variables (r values of 0.90, 0.87, and 0.82 for end-diastolic gradients, mean-diastolic gradients, and mitral valve area, respectively). Group II also showed excellent correlation of end-diastolic gradients (r = 0.80) and mean diastolic gradients (r = 0.87), but poor correlation of the mitral valve areas (r = 0.17; p = NS) by the two techniques. Doppler echocardiography can accurately measure transmitral gradients both before and after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Evaluation of spatial R maximum cardiac vector changes in exercise testing: pre-exercise versus post-exercise measurements.

R wave amplitude changes during exercise have been a controversial issue as both increase and decrease in amplitude have been reported in patients with coronary arterial disease. This variability in response is attributed to change in position and heart axis on exercise. In view of this limitation, this study evaluated the change in spatial R maximum amplitude on exercise, which should not be affected by the above factors. Twenty patients with ischaemic heart disease (male 20, age 38-61 years) and 9 control subjects (male 9, age 32-65 years) were studied. Orthogonal leads, X, Y, Z were recorded using corrected Frank lead system on a stereokinematic vectorcardiograph (Tonnies). The magnitude of spatial R maximum cardiac vector increased from 0.1 to 0.6 mV in 8/9 control subjects and decreased or showed no change in 18 of the 20 patients with coronary arterial disease. In the control group, the mean value at the end of exercise (0.98 +/- 0.34 mV) was significantly less (P less than 0.01) as compared to pre-exercise value (1.09 +/- 0.2 mV). Our preliminary observations thus indicate that, with exercise, the magnitude of spatial R maximum cardiac vector decreases or shows no alteration in height in patients with coronary arterial disease whereas it increases in normal subjects.

Adult↗
PubMed1989

Comparative Doppler evaluation of the monostrut and older convexo-concave Björk-Shiley mitral prosthetic valve.

Doppler echocardiography was performed in 104 patients with a Björk-Shiley prosthetic valve in the mitral position. Valves of size 25 mm and 27 mm were inserted in 39 and 65 patients, respectively. Each valve had two models; the older convexo-concave model (22 and 40, of 25 and 27 mm size, respectively). Inflow velocities were recorded using Doppler techniques and the gradients calculated using the Bernoulli principle. The area of the mitral valve was determined by the T1/2 method. Comparison of the two models for both sizes did not reveal any significant differences in either the gradients across the valves or the area of the valve. Trivial mitral regurgitation was detected in a higher percentage of monostrut valves (18% and 20% for the 25 and 27 mm older convexo-concave models and 59.9% and 52% for the 25 and 27 mm monostrut valve). We conclude that the newer monostrut model of the Björk-Shiley valve in the mitral position does not offer any additional haemodynamic benefit.

Adolescent↗
PubMed1989

Diagnosis of pulmonary venous obstruction by Doppler echocardiography.

A 1 1/2-year-old female patient with atrial and ventricular septal defects and severe pulmonary arterial hypertension was found to have discrete stenosis of left upper and middle lobe pulmonary veins. The diagnosis was made by cross-sectional and Doppler echocardiography. The findings were confirmed at cardiac catheterization and operation. Pressure gradients across the pulmonary vein stenosis as obtained by Doppler echocardiography correlated well with those measured at cardiac catheterization.

Cardiac Catheterization↗
PubMed1989

Electrophysiologic evaluation of patients with hypertrophic cardiomyopathy.

Ten consecutive patients with hypertrophic obstructive cardiomyopathy proven by echocardiography were subjected to detailed electrophysiologic evaluation and 24-hour ambulatory monitoring to detect the spectrum of arrhythmias and to identify their clinical correlates, if any. Two patients presented with syncope and the others with varying grades of dyspnea and angina. Ambulatory monitoring revealed isolated ventricular ectopics in five patients including couplets in two cases and runs of atrioventricular dissociation in two patients. Four patients had a normal study. Electrophysiologic evaluation demonstrated inducible nonsustained ventricular tachycardia in two patients (one with syncope and the other without syncope), short runs of supraventricular tachycardia in one (with a history of syncope), an accessory atrioventricular connexion in one patient (without any inducible arrhythmia), short atrio-His interval with minimal prolongation on incremental atrial pacing in three patients and ventriculoatrial conduction in two patients. A variety of electrophysiologic abnormalities was demonstrated in patients with hypertrophic cardiomyopathy. In two patients with a history of syncope only a nonsustained tachycardia was inducible. Further studies are warranted to find out the significance of these arrhythmias.

Adult↗