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Biomedical subjects

A M Abdulla

Publications and source records attributed to A M Abdulla.

At least 19 recordsLinked to original sources
PubMed1991

Mexiletine versus quinidine as first-line antiarrhythmia therapy: results from consecutive trials.

The efficacy of mexiletine and quinidine in controlling ventricular couplets (VC) and ventricular tachycardia (VT) was compared in 156 trials (78 for each drug) in 114 consecutive patients. Forty-two patients received both drugs, whereas 36 patients were given mexiletine, and 36 patients received quinidine only. During acute drug testing, mexiletine was more effective than quinidine in controlling VC and VT (54 vs. 32 patients, respectively, P less than .001) and resulted in fewer proarrhythmic events (4 vs. 13, respectively, P less than .05). Mean duration of follow-up for mexiletine (27 +/- 14 mo) and quinidine (21 +/- 14 mo) did not differ. Long-term success was more frequent with mexiletine administration than quinidine administration (33/47 vs. 10/30 patients, respectively, P less than .01). The incidence of sudden death during follow-up with the two drugs did not differ overall, but more patients with ejection fraction greater than or equal to 40% died suddenly while taking quinidine than while receiving mexiletine (4/17 vs. 0/24, P less than .02). Mexiletine is as effective as quinidine for treating VC and VT and appears to be less proarrhythmic. It should be considered as an initial choice in the management of VC and VT.

Aged↗
PubMed1988

Computer-assisted learning compared with weekly seminars for teaching fundamental electrocardiography to junior medical students.

This study was designed to assess whether a self-study interactive computer program is more effective than weekly seminars for teaching fundamental skills of electrocardiographic interpretation to junior medical students. Forty-two students were assigned to the computer and 41 to the seminar group. A test was given to each participant at the beginning and end of each rotation. The computer group used a computer-assisted learning program, and the seminar group met weekly with a cardiologist to review electrocardiograms. Attendance at a minimum of 80% of the seminars or completion of 80% of the computer-assisted learning program was required for inclusion in the statistical analysis. The mean difference in test scores before and after study was 5.69 for the computer group and 4.36 for the seminar group (P less than .02 by one-tailed t-test). These results indicate that the computer group performed significantly better than the seminar group. We believe this difference to be educationally important.

Attitude↗
PubMed1987

Serial noninvasive evaluation of cardiovascular hemodynamics during pregnancy.

M-mode echocardiography, in combination with electrocardiography and phonocardiography, has been used to measure pulmonary capillary pressure as well as other cardiac functions. Serial hemodynamic evaluations by use of this technique were performed in seven healthy pregnant women in the recumbent position. Each patient had five studies: four antenatal studies and one postpartum study that served as a control. Mean pulmonary capillary pressure was within normal limits throughout pregnancy and the puerperium. Cardiac output did not increase significantly by the end of the first or second trimester but became elevated by 31% in the early third trimester. This elevation in cardiac output persisted until delivery and resulted from a comparable increase in heart rate. Stroke volume and ejection fraction did not change significantly, while peripheral vascular resistance fell, although not significantly, reaching a nadir at approximately 28 weeks of gestation. Our findings indicate that maternal cardiac output increases due to an increased heart rate and reduced afterload.

Adolescent↗
PubMed1987

Computer-aided learning: experiences, perspectives and promises.

Despite the recent strong interest in computer-aided learning, very few high quality programs are available. This article describes an authoring system that was designed to help faculty at medical schools develop a library of effective computer-based lessons. Features of the system include ease of authoring and the ability to incorporate natural language input by the learner, model complex situations, keep track of 100 performance variables and employ interactive laser video disk technology. The authors describe the experience that has been gained in the development and implementation of computer-aided learning at a medical school, and reflect on its future applications and value.

Computer Simulation↗
PubMed1987

How can we diagnose coronary heart disease in hypertensive patients?

Chest pain is a common complaint among hypertensive patients. Hypertension and coronary heart disease each may present with symptoms and signs that are clinically indistinguishable. Noninvasive testing by routine exercise stress testing and stress radionuclide angiography are not reliably predictive of ischemia resulting from obstructive epicardial coronary artery disease and should be abandoned for that diagnostic purpose. Noninvasive thallium-201 myocardial perfusion imaging for this purpose may prove to be a valuable tool, avoiding the risk and expense of coronary arteriography. However, carefully performed prospective studies are not available. Because of the high prevalence of both diseases, a high priority must be given to obtaining these data and evaluating other noninvasive methods (especially positron emission tomography) if they appear promising.

Cardiomegaly↗
PubMed1987

Cardiovascular effects of ritodrine tocolysis: a new noninvasive method to measure pulmonary capillary pressure during pregnancy.

The cardiovascular effects of ritodrine tocolytic therapy were assessed by noninvasive simultaneous recordings of indirect carotid pulse, electrocardiogram (ECG), phonocardiogram, and M-mode echocardiogram in 12 patients in preterm labor. The study was performed before and during infusion, and afterward when the patient was on oral drug therapy. Ritodrine therapy increased heart rate, left ventricular fractional shortening, pre-ejection period/left ventricular ejection time ratio, and cardiac index. A progressive rise in pulmonary capillary pressure was observed in all patients, exceeding 18 mmHg (the threshold for the development of pulmonary congestion) in six patients. Systolic arterial pressure, left ventricular end-diastolic dimension, and plasma protein oncotic pressure remained unchanged during therapy. Ritodrine therapy resulted in a significant drop in diastolic blood pressure and peripheral vascular resistance. This noninvasive means of measuring cardiovascular parameters, including pulmonary capillary pressure, may be useful in monitoring patients who develop significant cardiovascular side effects during tocolytic therapy.

Echocardiography↗
PubMed1984

Potentially lethal arrhythmias and their management in hypertrophic cardiomyopathy.

The prevalence of potentially lethal arrhythmias (PLA) in groups of patients with hypertrophic cardiomyopathy has been assessed, but the rate at which they develop (their incidence) during long-term follow-up has not been reported. Therefore, conduction system disease (CSD) (sick sinus syndrome and His-ventricular disease), ventricular couplets and ventricular tachycardia (VT) detected by routine electrocardiograms, periodic 24-hour Holter monitoring and periodic exercise stress testing were studied in 50 patients treated with large doses of beta-adrenergic blocking drugs who were followed for 2 to 14 years (mean 5.9). Sixteen PLAs detected at the beginning of observation were excluded from actuarial analysis for new PLAs . Twenty-one patients had 24 new PLAs (7 with CSD, 1 patient with sustained supraventricular tachycardia, 6 with ventricular couplets and 10 with VT); only 43% of these PLAs were heralded by new symptoms. In 6 patients, the arrhythmia caused symptoms and was identified by a routine electrocardiogram. The 3 patients with His-ventricular disease presented with syncope and required electrophysiologic confirmation of this diagnosis. In only 1 patient was a PLA (ventricular couplets) detected only by exercise testing. All other ventricular arrhythmias were detected by Holter monitoring. The incidence of CSD in 47 patients free of this condition at entry was 5% at 5 years and 33% at 10 years. The incidence of ventricular couplets or VT in 39 patients free of these at entry was 26% at 5 years and 75% at 10 years, and the incidence of VT only was 18% at 5 years and 40% at 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Bedside evaluation in cardiac emergencies. Criteria for rapid diagnosis.

Because timely diagnosis and treatment are essential in cardiac emergencies, every physician who provides primary critical care should master the art of cardiovascular examination. In particular, this requires patience and skill at auscultation, as subtle differences in murmurs, for example, often differentiate two conditions. With a tentative diagnosis, the physician can then choose only the necessary confirmatory tests.

Acute Disease↗
PubMed1984

The use of natural language entry and laser videodisk technology in CAI.

One reason for the limited use of computer-assisted instruction in medical education has been that the writing of lessons often requires complex programming skills. Recently developed authoring systems for microcomputers now permit teachers unfamiliar with computers to write realistic clinical simulations for use in both instruction and evaluation. The authors in this paper describe the use of an authoring system which incorporates two important features: student interaction with the computer by natural language entry at the keyboard and the use of the microcomputer to direct a random-access laser videodisk player. For the purpose of evaluation, memory registers are employed to assign scores to several aspects of performance and to derive monetary costs for components of patient assessment and treatment. Similar registers are used to codify instructions for altering the clinical state of the simulated patient. The realistic simulations facilitate both problem-based learning and the evaluation of several cognitive aspects of clinical competence.

Computer-Assisted Instruction↗
PubMed1983

Value of ventricular premature complex (VPC) morphology in the diagnosis of hypertrophic cardiomyopathy.

Experimental and clinical studies have established the value of ventricular premature complexes (VPC) with a QR pattern in the diagnosis of occult antecedent myocardial infarction. However, the clinical significance of a QR pattern VPC in patients with hypertrophic cardiomyopathy has not been previously evaluated. In order to study this, we examined the ECGs and 24-hour Holter monitor records of 45 consecutive patients with hypertrophic cardiomyopathy and 106 consecutive patients with various other diseases. A QR pattern VPC in the precordial leads with a Q greater than or equal to 40 ms and a Q/R ratio greater than or equal to 0.20 had a specificity of 97%, a sensitivity of 29% and a predictive value of 80% in the diagnosis of hypertrophic cardiomyopathy. We conclude that a QR pattern VPC may be of value in the eclectic diagnosis of hypertrophic cardiomyopathy and that it is not specific for antecedent myocardial infarction as previously reported.

Cardiomyopathy, Hypertrophic↗
PubMed1983

Long-term medical management of hypertrophic cardiomyopathy: usefulness of propranolol.

Chronic therapy with propranolol has been shown to reduce the incidence of sudden death in patients with hypertrophic cardiomyopathy (HCM). However, the long-term effect of beta blockade on exercise capacity has not been studied adequately. Therefore, 32 patients with HCM (21 men), mean age of 47 years (range = 14 to 80 years), were evaluated for dyspnea and chest pain and underwent stress testing (ST) prior to therapy. At entry, ST was contraindicated in four patients, because of heart failure (three patients) and sustained supraventricular tachycardia (one patient). The remaining patients completed 4.9 +/- 3.2 min (mean +/- S.D.) of the Bruce protocol with a functional aerobic capacity (FAC) of 51 +/- 28%. All were placed on propranolol, unless a beta blocker with other characteristics was indicated. Dosage was adjusted to achieve a standing heart rate of 60 beats/min unless adverse effects occurred. At last follow-up, 25 patients were receiving 501 +/- 147 mg propranolol/day while the remainder received nadolol or metoprolol. On the most recent ST, patients exercised 6.6 +/- 3.1 min (38% increase), while mean FAC increased by 24% (both P less than 0.05). The FAC improved by more than 15% in 21, by less than 15% in five, was unchanged in five and was worse in only one, a noncompliant patient. The 21 patients with an FAC increment much greater than 15% exercised longer at entry than the remaining 11 (6.6 +/- 3.3 vs 3.9 +/- 2.8 minutes, P less than 0.05). The mean peak ST blood pressure-heart rate product of the group decreased from 26 550 to 17 898 (P less than 0.05), while the symptom scores of dyspnea and chest pain declined from 2.2 +/- 0.8 to 0.8 +/- 0.7 and from 1.4 +/- 1.0 to 0.3 +/- 0.8, respectively (both P less than 0.001). We conclude that beta blockade produces sustained improvement in exercise capacity. Improvement was greatest in those with the least initial impairment, and appears to be related to a reduction in blood pressure-heart rate product.

Adolescent↗
PubMed1983

Rhythm disturbances in hypertrophic cardiomyopathies: relationship to symptoms and the effect of 'complete' beta blockade.

Potentially lethal arrhythmias (PLA) are common in hypertrophic cardiomyopathies and are implicated in sudden death. We have demonstrated that propranolol is effective in controlling symptoms, but have not previously evaluated its effect on PLA. Our protocol for long-term management has been applied to 50 patients followed for 2 to 14 years (mean 5.9 years). No patient was excluded because of disease severity or complications. The only reason for exclusion was non-compliance with the protocol. At entry, Holter monitoring revealed 16 PLA in 13 patients (sustained supraventricular tachycardia (SSVT) in two, sinus node dysfunction (SSS) in three, paired beats (PB) in five, and ventricular tachycardia (VT) in six). All patients were initially begun on propranolol, unless a different beta blocker was indicated. Dosage was adjusted to a standing heart rate of 60 beats/min unless adverse drug effects developed. Holter monitoring during follow-up identified 24 new PLA in 21 patients (SSVT = 1, SSS = 4, His-Purkinje disease = 3, VT = 10, and PB = 6). The total number of identified PLA is now 40 in 30 patients. Concurrent symptoms of syncope, presyncope and palpitations were of limited value in identifying PLA because of a lack of predictive accuracy (76%, 64% and 29%, respectively). Invasive electrophysiologic study or dosage adjustment proved that beta blockade was not responsible for the conduction system disorders observed in 10 patients requiring pacemaker insertion. beta-Blockade completely suppressed VT in two patients, PB in five, and SSVT in two.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗