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Biomedical subjects

Alan H Kadish

Publications and source records attributed to Alan H Kadish.

22 records · Page 2Linked to original sources
PubMed2002

Acute blood pressure effects at the onset of supraventricular and ventricular tachycardia.

This study was designed to assess the effects of tachycardia origin, the significance of atrial contribution, and the effects of left ventricular ejection fraction on hemodynamically tolerated ventricular tachycardia (VT) and supraventricular tachycardia (SVT). Forty-one subjects with inducible hemodynamically tolerated VT (n = 24) or SVT (n = 17) with mean ages of 60 +/- 13 and 40 +/- 16 years and mean ejection fractions of 32 +/- 15% and 59 +/- 5%, respectively, were studied. VT and SVT were induced by standard techniques, and femoral arterial blood pressure (BP) was recorded for 30 seconds. After tachycardia termination, with >/=3 minutes between conditions, ventricular overdrive pacing was performed from the right ventricular (RV) apex and then the RV outflow tract, followed by atrioventricular (AV) pacing at the tachycardia cycle length. Mean BP was measured every 5 seconds. Linear regression methods were used to model BP response for the 2 groups. There was a significant increase in BP over the 20-second interval after the induction of VT and SVT (0.55 +/- 0.21 and 1.0 +/- 0.20 mm Hg/s, respectively, p <0.05). In patients with hemodynamically tolerated VT, RV apex and RV outflow tract pacing at the tachycardia cycle length decreased BP by 6.7 +/- 2.0 (p <0.002) and 4.7 +/- 2.5 mm Hg (p = 0.06), respectively. AV pacing at the tachycardia cycle length did not improve BP compared with RV pacing alone. In patients with SVT, RV apex and RV outflow pacing at the tachycardia cycle length decreased BP by 5.6 +/- 2.9 (p = 0.05) and 4.1 +/- 2.7 mm Hg (p = 0.12), respectively. However, AV pacing at the tachycardia cycle length was associated with improved BP response over RV pacing alone. Increased age and lower ejection fraction adversely influenced BP response in the VT group and longer cycle length, and higher preinduction BP favorably influenced BP response in the SVT group. The determinants of BP response after tachycardia onset are complex and differ in patients with SVT and VT.

Adult↗
PubMed2002

Predictors of appropriate implantable cardioverter-defibrillator therapy in patients with idiopathic dilated cardiomyopathy.

Evaluating predictors of appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with idiopathic dilated cardiomyopathy (IDC) may be helpful in developing risk stratification strategies for these patients. Fifty-four patients with IDC underwent ICD implantation and were followed up. Twenty-three patients (42%) had a class I indication for ICD implantation; the remaining patients underwent implantation for multiple risk factors for sudden death including left ventricular dysfunction, nonsustained ventricular tachycardia, syncope, or positive electrophysiologic study results. Clinical, electrocardiographic, and electrophysiologic data were collected. Appropriate ICD therapy was defined as an antitachycardia pacing therapy or shock for tachyarrhythmia determined to be either ventricular tachycardia or ventricular fibrillation. Appropriate ICD therapy was observed in 23 patients (42%). There was a significant difference in use of beta-blocker therapy between patients who did and did not have appropriate ICD therapy (p <0.0003). Cox regression analysis identified the following univariate predictors (p <0.1): class I indication (p <0.005) and lack of use of beta-blocker therapy (p <0.0007). In multivariate analysis, only lack of beta-blocker use (relative risk 0.15, 95% confidence intervals 0.05 to 0.45; p <0.0007) was identified as a predictor of appropriate ICD therapy. Of the patients who received ICD therapy, only 4 (17%) were taking beta blockers, whereas 21 of the 31 patients (68%) who did not receive ICD therapy were treated with beta blockers (p <0.0003). In patients with IDC selected for ICD implantation, the most consistent predictor of appropriate ICD therapy was lack of beta-blocker use. Attempts should be made to administer beta blockers to these patients, if tolerated.

Adrenergic beta-Antagonists↗
PubMed2002

Older age is the strongest predictor of postoperative atrial fibrillation.

BACKGROUND: Identification of patients vulnerable for atrial fibrillation (AF) after major thoracic surgery will allow targeting those most likely to benefit from prophylactic therapy. The goal of the current study was to evaluate the accuracy of easily available clinical characteristics for the prediction of this complication. METHODS: Patients undergoing major elective thoracic surgery were chosen from an ongoing prospective database. RESULTS: Postoperative in-hospital AF occurred in 79 (15%) of 527 patients Using cut-point methodology and logistic regression, the authors identified two preoperative risk factors independently associated with AF: age 60 yr or older (P = 0.0007) and heart rate 74 beats/min or greater on preadmission electrocardiogram (P = 0.005). The odds of developing AF increased by a factor of 2.5 (95% confidence interval, 1.7-3.4; P < 0.0001) between incremental age categories (< 60 yr, 60-69 yr, > or = 70 yr) and by a factor of 2.3 (95% confidence interval, 1.4-3.8; P < 0.0007) between heart rate categories (< 74 beats/min, > or = 74 beats/min). The combination of age 60 yr or older and preoperative heart rate 74 beats/min or greater predicted AF with a sensitivity of 73% and specificity of 57%. Maximum P-wave duration as measured from standard electrocardiogram did not differentiate patients who did or did not develop AF. Patients who developed AF had a higher incidence of postoperative pneumonia (14 vs. 4%; P = 0.001), acute respiratory failure (8 vs. 1.6%; P = 0.01), greater hospital stay (17 +/- 17 vs. 10 +/- 9 days; P = 0.001) and 30-day mortality (11 vs. 3%; P = 0.001) when compared with those who did not develop AF, respectively. CONCLUSIONS: Advanced age and preoperative heart rate identify patients at high risk for development of AF after thoracic surgery. Postoperative AF occurs more frequently in patients with greater postoperative morbidity and length of hospitalization.

Adult↗