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Each year, pacemaker therapy is prescribed to approximately 900,000 persons worldwide. Current pacemaker devices treat bradyarrhythmias and tachyarrhythmias and, in some cases, are combined with implantable defibrillators. In older patients, devices that maintain synchrony between atria and ventricles are preferred because they maintain the increased contribution of atrial contraction to ventricular filling necessary in this age group. In general, rate-responsive devices are preferred because they more closely simulate the physiologic function of the sinus node. Permanent pacemakers are implanted in adults primarily for the treatment of sinus node dysfunction, acquired atrioventricular block, and certain fascicular blocks. They also are effective in the prevention and treatment of certain tachyarrhythmias and forms of neurocardiogenic syncope. Biventricular pacing (resynchronization therapy) recently has been shown to be an effective treatment for advanced heart failure in patients with major intraventricular conduction effects, predominately left bundle branch block. Many studies have documented that pacemaker therapy can reduce symptoms, improve quality of life and, in certain patient populations, improve survival. [ABSTRACT FROM AUTHOR]

To assess determinants of left ventricular filling time at rest simultaneous phonocardiograms, M mode echocardiograms, and indirect carotid pulse traces were performed on 50 patients with atrial fibrillation. Thus the effect of random variation in RR interval in the absence of atrial contraction on the inter-relation between systolic and diastolic events could be seen. Left ventricular filling time was closely related to RR interval and affected by it to a much greater extent than ejection time, so that filling time became very short when heart rate was fast. Two mechanisms were, however, identified whereby filling time was preserved: (a) prolongation of filling during the pre-ejection period of the following cycle, so that when the RR interval was less than 400 ms all of ventricular filling frequently occurred at this time; and (b) abbreviation of the QA2 interval of the succeeding beat with reduced filling, so that mitral valve opening occurred early. Changes in the duration of isovolumic contraction or relaxation time were not involved, neither could alteration in left ventricular contractile state resulting from variation in the interval between beats be shown to affect time at rest. The striking sensitivity of left ventricular filling time to rapid heart rate in atrial fibrillation suggests that it may be a major factor limiting cardiac performance. Diastolic as well as systolic events should, therefore, be taken into account when the effects of drugs or other physiological manoeuvres are studied in these patients. [ABSTRACT FROM PUBLISHER]

Cardiac catheterization has been increasingly utilized to evaluate coronary artery disease in patients with end stage liver disease (ESLD). It is known in other populations that radial access reduces access site complications;however, there is a paucity of data in ESLD patients. We investigated vascular and bleeding complications rates between trans-femoral and trans-radial cardiac catheterizations in this high risk population. In this retrospective cohort study, three hundred and thirty four ESLD patients were identified between August 2004 and December 2012 who had undergone trans-femoral (femoral group) or trans-radial (radial group) cardiac catheterizations at our institution. The radial group was not significantly different from the femoral group in age (p = 0.056), proportions of genders (p = 0.85), and weight (p = 0.19); however, compared to the femoral group, the radial group had significantly lower blood pressure (p < 0.0001), hemoglobin (10.4 ± 1.9 vs 11.1 ± 2.02 g/dL, p = 0.001), and hematocrit (30.3 ± 5.7% vs 32.6 ± 6.0%, p < 0.0006), and had a significantly higher INR (1.94 ± 1.16 vs 1.59 ± 0.62, p = 0.0001). In terms of vascular complications, the radial group had a significantly lower rate of pseudoaneurysms (0% vs 3.7%, p = 0.019) than the femoral group. While there were no bleeding complications in either group or differences in transfusion requirements, there was a significantly lower percentage drop in hematocrit in the radial group compared to the femoral group (5.4% vs 7.8%, p = 0.039). In conclusion, trans-radial catheterization is associated with lower rates of vascular access site complications compared to trans-femoral catheterization.

The optimal preoperative cardiac evaluation strategy for patients with end-stage liver disease (ESLD) undergoing liver transplantation remains unknown. Patients are frequently referred for cardiac catheterization, but the effects of coronary artery disease (CAD) on posttransplant mortality are also unknown. We sought to determine the contribution of CAD and multivessel CAD in particular to posttransplant mortality. We performed a retrospective study of ESLD patients undergoing cardiac catheterization before liver transplant surgery between August 1, 2004 and August 1, 2007 to determine the effects of CAD on outcomes after transplantation. Among 83 patients who underwent left heart catheterization, 47 underwent liver transplantation during the follow-up period. Twenty-one of all ESLD patients who underwent liver transplantation (45%) had CAD. Fifteen of the transplant patients with CAD (71%) had multivessel disease. Among transplant patients, the presence of multivessel CAD (versus no CAD) was predictive of mortality (27% versus 4%, P = 0.046), increased length of stay (22 versus 15 days, P = 0.050), and postoperative pressor requirements (27% versus 4%, P = 0.029). Interestingly, neither the presence of any CAD nor the severity of stenosis in any single coronary artery predicted mortality. Furthermore, none of the traditional clinical predictors (age, gender, diabetes, creatinine, ejection fraction, and Model for End-Stage Liver Disease score) were predictive of mortality among transplant recipients. In conclusion, multivessel CAD is associated with higher mortality after liver transplantation when it is documented angiographically before transplantation, even in the absence of severe coronary artery stenosis. This study provides preliminary evidence showing that there may be significant prognostic value in coronary angiography as a part of the pretransplant workup., (© 2010 AASLD.)

Patients with end-stage liver disease (ESLD) are predisposed to bleeding complications due to thrombocytopenia, reduced synthesis of coagulation factors, and increased fibrinolytic activity. The exact incidence of vascular access site and bleeding complications related to cardiac catheterization in this group remains unknown. Eighty-eight consecutive patients with ESLD who underwent left-sided cardiac catheterization from August 2004 to February 2007 were identified. Eighty-one patients without known liver disease matched for age, gender, and body mass index who underwent left-sided cardiac catheterization during the same period were chosen as the control group. Vascular complications were defined as hematoma >5 cm, pseudoaneurysm, arteriovenous fistula, or retroperitoneal bleeding. Patients with ESLD had lower baseline mean hematocrit (32.3 +/- 6.0% vs 39.2 +/- 6.2%, p <0.001) and mean platelet count (90.1 +/- 66.3 vs 236.1 +/- 77.1 x 10(9)/L, p <0.001) compared with controls. They also had higher mean serum creatinine (1.9 +/- 1.7 vs 1.2 +/- 0.8 mg/dl, p = 0.002) and mean international normalized ratio (1.6 +/- 0.7 vs 1.1 +/- 0.2, p <0.001). There were more complicated pseudoaneurysms in the patients with liver failure (5.7% [5 of 88]), compared with 0% in controls (p = 0.029). Patients with ESLD had lower starting hemoglobin levels and greater reductions in hemoglobin after cardiac catheterization, resulting in greater need for packed red blood cell transfusion (16% vs 4%, p = 0.008), fresh frozen plasma (51.7% vs 1.2%, p <0.001), and platelet transfusions (48.3% vs 1.2%, p <0.001). Major bleeding was higher in the ESLD group (14.8% vs 3.7%, p = 0.014), driven mainly by the need for blood transfusion. In conclusion, despite severe coagulopathy, left-sided cardiac catheterization may be performed safely in this patient population, with correction of coagulopathy and meticulous attention to procedural technique.

Infective endocarditis is seen with increasing frequency in older patients. This increase is due to the general aging of the population, improved survival of patients with congenital and valvular heart disease, and the increasing use of catheters and other prosthetic devices with resulting higher incidence of nosocomial endocarditis. In older patients, infective endocarditis frequently develops in the absence of underlying structural heart disease; atheromatous deposits and mitral annular calcification are two important risk factors in this population. Infective organisms in older patients are frequently enterococci and other gastrointestinal tract bacteria. A marked febrile response is uncommon whereas central nervous system symptoms are more common in older patients. Transesophageal echocardiography can be performed safely and is a major diagnostic tool with sensitivity of more than 90% in detecting vegetations as small as 2-5 mm. Appropriately drawn blood cultures provide bacteriologic diagnosis in 80%-99% of patients. Prolonged antibiotic therapy may be required in many instances depending on the infective organism. Early surgical therapy is advisable for patients who develop heart failure as a result of severe acute aortic valvular regurgitation. Valve replacement surgery can be performed with acceptable mortality and morbidity even in very elderly patients., (Copyright 2003 Le Jacq Communications, Inc.)