Search PubMed⌕ Search

Biomedical subjects

D Ward

Publications and source records attributed to D Ward.

At least 163 records · Page 9Linked to original sources
PubMed1989

Comparison of adenosine and verapamil for termination of paroxysmal junctional tachycardia.

The effects of intravenous adenosine and intravenous verapamil on paroxysmal junctional tachycardia were compared in 20 patients undergoing invasive cardiac electrophysiologic study. In 13 patients the diagnosis was of a reentrant tachycardia using an extranodal accessory connection (atrioventricular [AV] reentrant tachycardia); 5 of these patients had overt preexcitation in sinus rhythm, 4 had concealed accessory connections and 4 had latent or intermittent preexcitation. In 7 patients the diagnosis was of an AV nodal reentrant tachycardia. Administration of adenosine resulted in termination of tachycardia in all 20 patients at a mean dose of 0.125 mg/kg (range 0.05 to 0.20). Although termination of tachycardia was frequently accompanied by atrial and ventricular premature complexes, no significant arrhythmias were observed after conversion. Administration of verapamil (0.145 mg/kg) resulted in termination of tachycardia in 19 of 20 patients but was followed by symptomatic arrhythmias in 2: preexcited atrial flutter in 1 patient and preexcited atrial tachycardia in another. Latent or intermittent preexcitation was unmasked in 4 of 4 patients immediately after termination of tachycardia by adenosine. Termination of tachycardia by verapamil revealed preexcitation in only 1 of these 4 patients. Analysis of results in terms of successful termination of tachycardia, absence of significant arrhythmias after conversion and unmasking of latent or intermittent preexcitation reveals that adenosine therapy was satisfactory in all 20 patients, whereas verapamil was satisfactory in only 14 of the 20 patients (p less than 0.05). All 6 of the patients with unsatisfactory responses to verapamil had AV reentrant tachycardia. These results suggest that adenosine has particular advantages over verapamil as acute treatment for patients presenting with an AV reentrant tachycardia.

Adenosine↗
PubMed1989

Misuse of verapamil in pre-excited atrial fibrillation.

Of 18 patients who attended accident and emergency departments with pre-excited atrial fibrillation, 10 were inappropriately treated with intravenous verapamil. The reason for the inappropriate treatment was misdiagnosis of the arrhythmia, although diagnostic electrocardiograms were available for all patients: in only 3 of the 18 patients was the correct diagnosis made before intervention. Misdiagnosis occurred because of failure to consider pre-excitation as a possible diagnosis, rather than bias towards a single alternative arrhythmia. The use of intravenous verapamil was associated with deterioration in the clinical condition of 6 patients and continued arrhythmia in all 10.

Adolescent↗
PubMed1989

Weight control and calorie expenditure: thermogenic effects of pre-prandial and post-prandial exercise.

The thermogenic effects of pre- and postprandial exercise was examined in seven lean active females. Energy expenditure was measured for 3 h via open circuit indirect calorimetry after four separate treatments: Exercise Only (25 min treadmill run at 60% VO2 max), Meal Only (910 kcal mixed meal), Exercise-Meal and Meal-Exercise. The thermogenic response to the Exercise-Meal treatment was similar to the Meal Only treatment. However, the Meal-Exercise treatment resulted in a greater energy expenditure than the Meal Only and Exercise-Meal treatments. The Exercise Only treatment showed the lowest thermogenic response. These data suggest that exercise following a meal would be more beneficial than exercise before a meal in increasing and maintaining an elevated energy expenditure.

Adult↗
PubMed1989

Activity of 5-fluorouracil, mitomycin C, and methyl CCNU in inoperable adenocarcinoma of pancreas.

Twenty-two patients with inoperable adenocarcinoma of the pancreas were treated with 5-fluorouracil (5-FU), mitomycin C (Mito-C), and 1(-2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU). Fifteen were evaluable by completing 2 months of therapy. Two patients achieved a complete remission with the above combination. A partial remission seen in four other patients, which produced a response rate of 40% of evaluable, and 27% of entered, patients. Three had stable disease. The average time to progression in this study was 8 months. This combination was well tolerated and no deaths were secondary to drug therapy. Mucositis, leukopenia, thrombocytopenia, and hyperpigmentation were the significant toxicities seen in this study. These observations are worthy of further investigation.

Adenocarcinoma↗
PubMed1989

Public health nursing and The Future of Public Health.

The recent Institute of Medicine report, The Future of Public Health, reviews the history, current status, and potential of the public health system in the United States, and makes detailed recommendations for its revitalization. Although public reports such as this risk speedy obscurity, many are used by planners and legislators and a few exert significant influence. Public health nursing is inadequately represented in this potentially influential document, and this has unfortunate implications for public health nursing.

Forecasting↗
PubMed1989

Diagnostic value of comparison of ventriculoatrial interval during junctional tachycardia and right ventricular apical pacing.

We postulated that comparison of ventriculoatrial intervals during junctional tachycardia and during right ventricular apical pacing may provide similar diagnostic information to that obtained from the insertion of ventricular extrasystoles during tachycardia. We studied 39 patients with either atrioventricular reentrant tachycardia (AVRT) (23 patients) using a single atrioventricular accessory pathway or atrioventricular nodal reentrant tachycardia (AVNRT) (16 patients). Ventriculoatrial [VA] intervals were measured during tachycardia, during right ventricular apical pacing at the same rate as that of the tachycardia and following a ventricular extrasystole delivered at the minimum reset interval (minimum prematurity of a ventricular extrasystole required to advance the subsequent atrial complex by more than 10 msec). The difference between the minimum VA interval during tachycardia and during ventricular pacing was closely related to both the minimum reset interval (r = 0.92, P less than 0.001) and the difference between the minimum VA interval during tachycardia and following a ventricular extrasystole delivered at the minimum reset interval (r = 0.97, P less than 0.001) in the 23 patients in whom the minimum reset interval could be determined. The ratio between the minimum ventriculoatrial interval during tachycardia and ventricular pacing could be determined in all cases and was between 1.53 and 1.68 in AVRT with right free wall (two patients), 0.94 and 1.29 with anteroseptal (three patients), 0.91 and 1.08 with posteroseptal (five patients) and 0.48 and 0.71 with left free wall (13 patients) pathways, while it was between 0.32 and 0.27 in AVNRT (16 patients). The ratio was more discriminative when corrected for ventricular latency and was also useful when calculated from the high right atrial electrogram. We concluded that comparison of ventriculoatrial intervals during junctional tachycardia and during right ventricular apical pacing can discriminate between the mechanisms of tachycardia and the site of pathway. It provides similar information to that obtained from ventricular extrasystoles during tachycardia with the advantage that it can be determined in all cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Atrioventricular Node↗
PubMed1989

Caregiving.

Explore the source record for details and available documents.

Aged↗
PubMed1988

Prospective evaluation of clinical assessment, exercise testing and signal-averaged electrocardiogram in predicting outcome after acute myocardial infarction.

The relative value of exercise testing, late potentials and simple clinical assessment in predicting ischemic and arrhythmic events during follow-up after acute myocardial infarction (AMI) was investigated prospectively in a population of 176 consecutive patients surviving to 7 days after AMI. During 15 +/- 9 (range 3 to 24) months of follow-up, there were 23 ischemic events (2 fatal reinfarctions, 6 nonfatal reinfarctions and 16 patients who underwent coronary artery bypass grafting, 1 after reinfarction) and 11 arrhythmic events (7 symptomatic ventricular tachycardias and 4 sudden cardiac deaths). Stepwise multiple regression analysis showed that out of 11 variables, including exercise testing, late potentials and clinical data, exercise testing was the only independent variable predicting the occurrence of ischemic events (p less than 0.05 not including coronary artery bypass grafting and p less than 0.002 including it). Arrhythmic events were predicted, in order of importance, by Killip class (p less than 0.05), late potentials (p less than 0.005), previous AMI (p less than 0.009), occurrence of in-hospital complications (p less than 0.005) and non-Q-wave AMI (p less than 0.02). The presence of late potentials provided independent prognostic information from the Killip class and the result of exercise testing in predicting both arrhythmic and ischemic events. Exercise testing, late potentials and clinical assessment provide complementary prognostic information in postinfarction patients.

Adult↗
PubMed1988

Pacemaker policy.

Explore the source record for details and available documents.

Bradycardia↗
PubMed1988

Theoretical evaluation of the Rosenblueth hypothesis.

Rosenblueth's hypothesis states that atrioventricular (AV) nodal conduction delay and Wenckebach periodicity of AV transmission are not due to overall decremental conduction within the AV node but are due to a single step delay which is caused by a special element or layer of the AV nodal tissue. This paper discusses some theoretical considerations which allow detailed evaluation of the original hypothesis. Two artificial conduction structures which incorporate the Rosenblueth phenomenon are presented and tested by theoretical experiments that consider the potential of these structures to produce (a) basic pattern of Wenckebach periods, (b) decremental shortening of RR intervals during Wenckebach periods. These experiments are also employed to test whether or not the Rosenblueth concept can be used to explain (c) appropriate dependence of AV conduction changes on the prematurity of atrial depolarizations, and of (d) alternating cycle lengths such as may be seen with atrioventricular reentrant tachycardia. The results of the theoretical considerations show that the original concept of the Rosenblueth hypothesis is sufficient to explain (a) but it cannot be used for realization of (b), (c) and (d). A modification of the original concept complying with both (a) and (b) is proposed. This modified structure can also reproduce (c), but not simultaneously with (b). The experiments show that anisotropy of intra AV nodal conduction may create an electrophysiological mechanism of single-step delay. Different anisotropic conduction structures have to be considered to reproduce phenomenon (d).

Atrial Function↗
PubMed1988

Balloon dilatation of the aortic valve: limited success and early restenosis.

Balloon dilatation of the aortic valve was attempted 16 times in 15 patients with severe aortic stenosis. None died but one had a transient stroke after the procedure. At dilatation the gradient across the aortic valve was reduced by greater than 30% in 69% of patients and the Gorlin valve area (calculated in 7/15 patients) increased by 30% in half. But a comparison of Doppler gradients measured before and one to two days after dilatation in 11 patients showed a greater than 30% reduction in the simultaneously measured gradient in only four. Doppler gradient was the most accurate predictor of symptomatic benefit and a fall in Doppler gradient persisted mainly in patients whose peak to peak gradient fell by at least 40% at the time of the procedure. Balloon dilatation of the aortic valve is a relatively safe procedure but it is less successful than previous reports suggest, perhaps because of early restenosis. Some forms of aortic stenosis may be more amenable to this procedure than others.

Aged↗