Biomedical subjects

Sohail A Hassan

Publications and source records attributed to Sohail A Hassan.

3 recordsLinked to original sources

PubMed2005

Bundle branch block patterns, age, renal dysfunction, and heart failure mortality.

BACKGROUND: The determinants of bundle block patterns and their relationship to mortality in heart failure patients is not completely understood. METHODS: We evaluated 2907 consecutive patients admitted to an intensive care unit with decompensated heart failure over 8 years. Clinical and echocardiographic factors were analyzed using multivariate techniques. All-cause mortality was available on greater than 99.0% of patients at a median of 23 months after discharge. RESULTS: Right and left bundle branch blocks occurred in 211 (7.3%) and 386 (13.2%), p<0.0001. Older age, decreased left ventricular ejection fraction, and renal dysfunction were all found to be independently associated with bundle branch block patterns. Mortality rates for the subgroups of QRS<120 ms, right bundle branch block and left bundle branch block, over a mean follow-up of 23.4+/-2.6 months were 46.1%, 56.8% and 57.7%, p<0.0001 for comparison of QRS<120 ms versus either bundle pattern. Cox proportional hazards model adjusting for age, sex, ejection fraction, and renal function demonstrated graded decrements in survival in those with QRS<120 ms, right bundle branch block and left bundle branch block, p=0.03. CONCLUSIONS: In patients hospitalized with severe heart failure, age, left ventricular dysfunction, and renal dysfunction are associated with bundle branch block patterns. When controlling for these factors, bundle branch block patterns are independently associated with slightly higher all cause mortality after discharge.

Age Factors↗

PubMed2005

Coronary sinus lead placement via the internal jugular vein in patients with advanced heart failure: a simplified percutaneous approach.

BACKGROUND: Placement of coronary sinus (CS) leads is usually achieved via the left cephalic-axillary-subclavian (CAS) venous system. In some cases, however, such as lack of venous access a right side approach is required. Cannulation of the CS via the right CAS vein is often technically difficult, leaving the right IJ vein as a suitable alternative. OBJECTIVE: The feasibility of IJ vein as a conduit for transvenous left ventricular (LV) pacing in patients with heart failure (HF) has not been reported. METHODS AND RESULTS: Between July 2002 and April 2004, we implanted 339 biventricular devices in patients with moderate-to-severe HF. In 15 patients with similar clinical characteristics, in whom the left CAS vein could not be used, the CS leads were placed via the right CAS venous system (n = 5) or the IJ vein (n = 10). The ten patients (6 men and 4 women; age 66 +/- 15 years; LV ejection fraction .19 +/- .07; QRS duration 183 +/- 35 ms) who required IJ CS lead placement had no procedure related complications and all retained appropriate LV pacing and showed significant improvement in HF symptoms after a median follow-up of 12 months (6 to 22 months). CONCLUSIONS: Thus, in patients with HF for whom the traditional CAS venous approach cannot be used (left side) or is technically difficult (right side), CS leads can be deployed safely via the right IJ vein. In these situations, it seems appropriate to consider this approach prior to the more invasive epicardial approaches.

Adult↗

PubMed2003

Rate-dependent effect of verapamil on atrial refractoriness.

OBJECTIVES: The purpose of this study was to determine whether verapamil has rate-dependent effects on the atrial effective refractory period (AERP). BACKGROUND: Block of calcium current (I(Ca)) and rapid component of the delayed rectifier potassium current (I(Kr)) by verapamil is frequency-dependent. This may result in variable effects of verapamil on the AERP, depending on the rate. METHODS: The subjects of this study were 30 adults with a mean age of 45 +/- 13 years who did not have structural heart disease. In 20 subjects, the AERP was measured at basic drive cycle lengths (BDCLs) of 650 to 250 ms, in 50 ms decrements, before and after infusion of 0.1 mg/kg verapamil. The effective refractory periods (ERPs) were measured in the setting of autonomic blockade in 10 subjects and without autonomic blockade in 10 subjects. Ten subjects served as a control group and received a saline infusion instead of verapamil. RESULTS: Verapamil significantly prolonged the AERP at BDCLs of 650 to 500 ms (p < 0.01 or p < 0.05) and significantly shortened the ERP at BDCLs of 300 and 250 ms (p < 0.01). In the control group, there were no significant differences between the baseline and post-saline measurements of ERP. CONCLUSIONS: Verapamil prolongs AERP at slow rates and shortens AERP at rapid rates. These findings are consistent with a predominant effect on I(Ca) at rapid rates and a predominant effect on I(Kr) at slow rates.

Adult↗