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Biomedical subjects

D Roy

Publications and source records attributed to D Roy.

At least 289 records · Page 16Linked to original sources
PubMed1987

Atrial natriuretic factor during atrial fibrillation and supraventricular tachycardia.

Plasma immunoreactive atrial natriuretic factor was measured in 10 patients with chronic atrial fibrillation before and after cardioversion to sinus rhythm, and in 14 patients during electrophysiologic evaluation of paroxysmal supraventricular tachycardia. The mean plasma concentration of atrial natriuretic factor in atrial fibrillation was 138 +/- 48 pg/ml and decreased to 116 +/- 45 pg/ml 1 hour after cardioversion to sinus rhythm (p less than 0.005). The mean plasma concentration of atrial natriuretic factor increased from 117 +/- 53 pg/ml in sinus rhythm to 251 +/- 137 pg/ml during laboratory-induced supraventricular tachycardia (p less than 0.005). Right atrial pressures were recorded in 12 patients; the baseline atrial pressure was 4.3 +/- 1.9 mm Hg and increased to 7.4 +/- 3.6 mm Hg during supraventricular tachycardia (p less than 0.005). A modest but significant linear relation was noted between the changes in plasma atrial natriuretic factor and right atrial pressure measurements during induced supraventricular tachycardia (r = 0.60, p less than 0.05). In conclusion, changes in atrial rhythm and pressure may be an important factor modulating the release of atrial natriuretic factor in the circulation and raised levels of this hormone may be a contributing factor for the polyuria and the hypotension associated with paroxysmal supraventricular tachyarrhythmias.

Aged↗
PubMed1987

Application of an individually predicted dosage of amitriptyline to the treatment of depression.

The treatment of depressed patients with a fixed dose of amitriptyline is compared to treatment with an individualized dose calculated by means of a simple pharmacokinetic test. Clinical response and the development of side-effects are compared between the two groups of patients. Although the numbers in the groups were small, the clinical results lend little support to the concept of a therapeutic range of plasma drug concentrations for amitriptyline, and none of the plasma concentrations was high enough to produce serious toxic effects. No obvious clinical advantage was observed in the predicted dose treatment group as assessed by a reduction in depression ratings. The dose prediction test did however more than halve the variance in blood drug concentrations, and its usefulness in preventing high and potentially toxic concentrations is indisputable.

Adult↗
PubMed1987

Early postinfarction ischemia: clinical, angiographic, and prognostic significance.

Early ischemia, defined as angina with transient ST-T changes during hospitalization, 24 hr or more after an acute myocardial infarction (MI), was observed in 79 (18%) of a consecutive series of 449 patients surviving an MI and catheterized a mean of 10 +/- 3 days after admission. Three clinical factors present 24 hr after admission could identify patients at low, medium, and high risk of factors had a risk greater than 50% and the 118 patients with Q wave MI, no previous angina, and absence of risk factors had a risk of less than 8%. The angiographic correlates of early ischemia were number of vessels with 70% or more stenosis (2.1 +/- 0.8 vs 1.7 +/- 0.8/patient, p less than .0001), number of diseased coronary artery segments (2.8 +/- 1.4 vs 2.1 +/- 1.2, p less than .0001), left anterior descending coronary involvement (77% vs 62% of patients, p = .01), number of normally contractile segments at jeopardy because of a coronary stenosis (1.9 +/- 1.3 vs 1.3 +/- 1.1/patient, p less than .0002), collateral circulation at jeopardy (24% vs 15% of patients, p less than .005), and fewer collateral vessels distal to a tight stenosis (59 vs 72% of patients, p = .04). The stepwise logistic regression retained one angiographic and two clinical independent predictors of early ischemia: number of diseased vessels (p = .0008), presence of a non-Q wave MI (p = .0027), and previous angina (p = .017).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1987

Long-term prognosis of patients with variant angina.

The long-term prognosis of variant angina and the factors influencing it were assessed in 217 consecutive patients hospitalized in our coronary care unit and followed for a mean of 65 months (range 2 to 123). Cardiac death occurred in 30 patients and an additional 54 experienced a nonfatal myocardial infarction. Survival at 1 and 5 years was 95% and 89%, respectively; survival without infarction was 83% and 69%. Coronary disease and the degree of disease activity were strong predictors of survival by Cox analysis. Survival at 1 year was 99%, and that at 5 years was 95% and 94%, respectively, for patients with one-vessel disease (n = 81) and for those without stenoses of 70% or greater (n = 87). Survival at 1 and 5 years was only 87% and 77% for those with multivessel disease (n = 40). The Cox analysis selected left ventricular function, initial treatment, extent score, duration of angina at rest, and disease activity as multivariate predictors of survival without infarction. Coronary disease was a strong predictor (p less than .0001) of survival without infarction by univariate analysis. Treatment with nifedipine, diltiazem, or verapamil improved survival without infarction compared with other medical treatment (p = .002). Myocardial infarction occurred most commonly soon after diagnosis in patients with a short history of angina at rest. Late coronary events were almost never preceded by resting angina.

Adult↗
PubMed1987

[Surgical treatment of ventricular tachycardia].

We present our clinical experience with 37 patients presenting with ventricular tachycardia who, between 1980 and 1986, underwent subendocardial resection, guided by per-operative mapping in 34 cases. An aneurysm of the left ventricle was present in 23 patients (62%), and an akinetic area in the remaining 14 patients. In every case the cause of ventricular tachycardia was an ischaemic heart disease. Prior to surgery, the global isotopic ejection fraction was 27 +/- 11% and the left ventricular end-diastolic pressure was 21 +/- 8 mmHg. The most common site of origin of the arrhythmia was the septum (26 cases, 77%). The mean area of resection was 26 +/- 16 cm2. Resection of a ventricular aneurysm was also performed in 23 cases, and 22 patients underwent coronary bypass. There were 4 early deaths (operative mortality rate : 10.8%) and 4 late deaths. The actuarial survival rate was 89 +/- 5% at 6 months and 72 +/- 9% at 24 months. One-half of the deaths was due to recurrence of the ventricular tachycardia. A post-operative electrophysiological study conducted in 30 patients proved negative in 28 (93%). Altogether, there were 6 immediate or late failures (16.2%) after a mean follow-up period of 18 months. The probability of a relapse-free, medication-free life or sudden death was 86 +/- 6% after 6 months and 82 +/- 7% after 24 months. The quality of life of the survivors war remarkable, since 86% of them (25/29 patients) remained in functional class 1 or 2 after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1986

Previous coronary artery bypass grafting as an adverse prognostic factor in unstable angina pectoris.

Among 252 patients hospitalized for unstable angina in 1982 and 1983, 54 (21%) had undergone coronary artery bypass grafting (CABG) a mean of 55 months earlier (range 1 to 168) (CABG patients). This group was compared with a group of 54 randomly selected patients with unstable angina without previous CABG (control patients). The 2 groups did not differ with respect to clinical characteristics at admission or hospital course. Coronary arteriograms, recorded in all but 4 CABG patients, revealed multivessel stenoses of at least 70% luminal diameter in 40 CABG and 32 control patients (p less than 0.05), but when patent grafts were considered, the groups were comparable. Overall, 48 of 112 grafts were totally occluded and 14 had stenoses at least 70% in diameter. Complete or almost complete revascularization was feasible in 39 of 52 control and only 9 of 42 CABG patients (p less than 0.001). By 1 year, 46 control patients and 20 CABG patients had undergone CABG or coronary angioplasty (p less than 0.001); 42 of 53 control patients and only 22 of 50 CABG patients were in functional class 0 or I (p less than 0.001). Cumulative adverse events (5 deaths, 10 myocardial infarctions and 15 cases of recurrent unstable angina) were more frequent in the CABG group, 20 vs 10 (p less than 0.05). Thus, although their clinical features and hospital course are similar, patients with unstable angina who have undergone previous CABG do not do as well as other patients with unstable angina because they are less amenable to revascularization.

Angina Pectoris↗
PubMed1986

Atrial natriuretic factor in human plasma.

A reproducible and sensitive radioimmunoassay (RIA) was developed to measure ANF in human plasma. Immunoreactive ANF was extracted from plasma with Sep-Pak cartridges, using 0.2% ammonium acetate (pH 4) with acetonitrile. The sensitivity of the assay was 3.9 pg/ml. The coefficient of variance for inter-assay and intra-assay was 16.8% and 6.8%, respectively. In normal healthy subjects (n = 67), ANF content was 11.9 +/- 1.3 pg/ml (mean +/- SEM). Significantly-higher ANF concentrations were found in proximal coronary sinus blood, being 6 to 37 times greater than in the peripheral circulation. Comparison of the prior extraction method with direct RIA revealed a good correlation (r = 91) in samples containing higher than 100 pg/ml ANF. No correlation was observed with lower values. The elution profiles of reverse-phase HPLC of peripheral and coronary sinus plasma extracts were similar but somewhat complex, with the main immunoreactive peak corresponding to a low-molecular-weight peptide.

Adult↗
PubMed1986

Usefulness of anticoagulant therapy in the prevention of embolic complications of atrial fibrillation.

The medical records of 254 patients with atrial fibrillation were reviewed to determine the incidence of embolic events in relation to type of cardiovascular disease, duration of atrial fibrillation, and use of anticoagulants. During a total follow-up of 833 patient-years in atrial fibrillation, there were 32 instances of systemic embolism: 21 involved the cerebral circulation and 11 were extracerebral. Thirty of these events occurred during 549 patient-years of follow-up without anticoagulation therapy (5.46 of 100 patient-years), while only two embolic events occurred during 284 patient-years on anticoagulants (0.7 of 100 patient-years). Thus, the incidence of embolism was eight times more frequent during the unanticoagulated period of observation in atrial fibrillation (p less than 0.002). The incidence of embolism during follow-up without anticoagulants was the same regardless of the presence or absence of mitral valve disease and regardless of whether atrial fibrillation was chronic or paroxysmal. The rate of serious hemorrhagic complications on anticoagulants was acceptably low (2.11 of 100 patient-years). We conclude that in this study population anticoagulant therapy reduced the risk of embolic complications of atrial fibrillation. The results also indicate that the use of anticoagulants should not be limited to patients with atrial fibrillation due to mitral valve disease.

Adult↗
PubMed1986

Long-term reproducibility and significance of provokable ventricular arrhythmias after myocardial infarction.

The long-term reproducibility and significance of inducible ventricular arrhythmias were assessed in 21 survivors of a myocardial infarction. Programmed ventricular stimulation performed a mean of 12 +/- 2 days (range 8 to 18) after infarction provoked ventricular fibrillation in 2 patients, sustained monomorphic ventricular tachycardia in 8 and nonsustained ventricular tachycardia in 11. Patients were restudied using the same protocol a mean of 8 +/- 2 months (range 4 to 11) after infarction. All patients underwent programmed ventricular stimulation studies in the absence of antiarrhythmic drug treatment. Ventricular tachyarrhythmias could be reinitiated in 16 patients (76%): ventricular fibrillation in 2, sustained ventricular tachycardia in 5 (monomorphic in 4) and nonsustained ventricular tachycardia in 9. A preponderance of inferior infarction was observed among patients with reinducible tachycardias (9 of 16 patients versus 0 of 5 with noninducible tachycardias) (p less than 0.05). No significant difference existed between patients with and without reinducible arrhythmias with respect to severity of coronary artery disease, degree of left ventricular dysfunction, occurrence of ventricular fibrillation in the acute phase of infarction and ventricular arrhythmias detected by 24 hour ambulatory electrocardiographic (Holter) monitoring. There was no significant difference between patients with and without a positive late study in stimulation thresholds, ventricular refractory periods, time interval between initial and repeat testing and use of beta-adrenergic blocking agents. During a mean follow-up period of 17 months (range 10 to 23) one patient with inducible sustained monomorphic ventricular tachycardia at both studies died suddenly. The remaining patients have survived follow-up without experiencing an arrhythmic event.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Successful treatment with streptokinase of renal vein thrombosis associated with oral contraceptive use.

The case of a 25-year-old diabetic female presenting with acute right main renal vein thrombosis associated with oral contraceptive usage is described. Rapid diagnosis with ultrasound and resolution of the thrombosis was accomplished with streptokinase. Ultrasound may be the diagnostic test of choice in selected patients with renal vein thrombosis. Streptokinase was an effective therapy in this case of acute renal vein thrombosis.

Adult↗
PubMed1986

Changes in lens protein in concentric fractions from individual normal human lenses.

The water soluble (WS), urea soluble (US) and urea insoluble (UI) fractions from individual human lenses 1.8 to 65 years of age were isolated from concentric fiber layers. In lenses younger than 19 years, a uniform distribution in the amount of WS, US and UI fractions was found throughout the entire lens. These fractions represent 83, 11.5 and 5.5%, respectively, of the lens dry weight. This composition was observed with the cortical fibers of all lenses examined up to the 65-year old. In the nuclear fiber layers, the proportion of US protein gradually increases in the third to fourth decade of lens growth and appears to have reached a maximum representing 22-24% of the nuclear fiber mass in 50-year and older lenses. A large increase in the amount of the UI fraction to 30% of the fiber mass was observed in lenses between the 5th and 6th decade of lens growth. The change from the cortical to nuclear composition occurs in a narrow region of the lens which becomes more peripheral with aging. The cortical WS fractions were characterized by well defined polyacrylamide gel bands in sodium dodecyl sulfate (SDS). Those of the nuclear fibers were broadened, especially in the 27/29 and 16/18 kilodalton (KD) region. The disappearance of the 20/22 KD bands in the inner cortical and nuclear fibers cannot be accounted for by the small increase in protein insolubilization in these regions of lenses 40 years or younger.

Adult↗
PubMed1986

Tumor growth enhancement and systemic responses of Ehrlich ascites carcinoma following intermittent whole body hyperthermia.

Intermittent whole body hyperthermia 42 degrees C (WBH(I) administered for 30 min daily during 7 days caused significant enhancement of the growth of Ehrlich ascites carcinoma. The tumoricidal effects of hyperthermia were evident from the cytological picture as well as from the increased activity of lysosomal enzyme of the tumor cells. Elevated plasma corticosteroid levels, adrenal hypertrophy, thymus involution and lymphocytopenia were observed in both normal and tumor bearing mice exposed to hyperthermia. The alterations were more marked in the tumor bearing groups. Withdrawal of treatment caused gradual restoration of stress effects. It appears that the tumoricidal effects of WBH(I) were counteracted and surpassed by the growth stimulatory effects induced probably by hormone mediated immunosuppression.

Adrenal Glands↗