Relation of brain natriuretic peptide level to extent of left ventricular scarring in patients with chronic heart failure secondary to ischemic cardiomyopathy.

Multiple factors influence brain natriuretic peptide (BNP) release in patients with heart failure. We hypothesized that extensive myocardial scarring could result in an attenuated BNP response. A total of 115 patients with New York Heart Association class III chronic heart failure and ischemic cardiomyopathy were evaluated for ischemia, hibernation, and myocardial scarring by dipyridamole-rubidium-positron emission tomographic scanning with fluorine-18, 2-fluoro-2-deoxyyglucose. Plasma BNP levels were determined within 2 weeks of the study. Left ventricular dimension and function were evaluated by echocardiography. Patients were categorized as having <33% myocardial scar (n=67) or>or=33% myocardial scar (n=48). BNP measurements were correlated with amount of myocardial scarring. Compared with patients with less scar, those with >or=33% scar had lower BNP levels (mean 317+/-364 vs 635+/-852 pg/ml, median 212 vs 357, p=0.016). Using multiple regression analysis, presence of scarring was associated with decreased BNP response (p=0.022). Further, patients with <33% scar in whom a higher BNP level was noted had more ischemia (51% vs 27%, p=0.01) and greater myocardial hibernation (22+/-14% vs 12+/-7%, p=0.02) compared with patients with >or=33% scar. In conclusion, in patients with chronic heart failure, a decreased BNP response indicated extensive myocardial scarring.

Alterations of regional myocardial function in a swine model of myocardial infarction assessed by echocardiographic 2-dimensional strain imaging.

BACKGROUND: Tissue Doppler strain and strain rate imaging have been introduced for quantitative assessment of regional myocardial function. These techniques are largely limited to the evaluation of overall longitudinal myocardial function. This study attempted to apply radial strain, circumferential strain, radial displacement, and strain-based torsion analysis to differentiating the infarct, adjacent, and remote zones in a swine model of myocardial infarction. METHODS: Seven pigs, body weight 24 to 26 kg, were subjected to myocardial infarction by occlusion of the left anterior descending coronary artery (LAD) and followed up for 8 weeks. Regional radial and circumferential deformations were quantified noninvasively by ultrasonic strain rate imaging before LAD occlusion, LAD occlusion immediately, and 4, 6, and 8 weeks after LAD occlusion. Strain-based left ventricular torsion was assessed at the same time points. RESULTS: Both radial and circumferential strains, and torsion, were decreased significantly in the LAD territory areas as a result of myocardial ischemia and infarction. There were no significant changes in radial and circumferential strains, or torsion, in the areas of adjacent and remote zones over time. CONCLUSIONS: These findings demonstrate that speckle-tracking strain imaging may be suitable for noninvasive quantification of left ventricular segmental function of ischemic heart disease.

Cardiovascular imaging in the management of atrial fibrillation.

Atrial fibrillation (AF) is he most commonly encountered arrhythmia in clinical practice, with an overall prevalence of 0.4% in the general population. Recent advances in technology and in the understanding of the pathophysiology of AF have led to more definitive and potentially curative therapeutic approaches. Echocardiography has a well-established role in the assessment of cardiac structure and function and risk stratification, and has become an essential part of the guidelines for management of AF. The development of intracardiac echocardiography has led to real-time guidance of percutaneous interventions, including radiofrequency ablation and left atrial appendage closure procedures for patients with AF. Other imaging modalities, including computed tomography and magnetic resonance angiography, have allowed for more accurate measurement and better understanding of the cardiac anatomy. We review the impact of various imaging modalities in the evaluation and management of AF.

The impact of hypogammaglobulinemia on infection outcome in patients undergoing ventricular assist device implantation.

BACKGROUND: Infection is a major comorbidity after ventricular assist device (VAD) placement. Defects in cellular immunity have been reported after VAD placement. However, to our knowledge, quantitative immunoglobulin G (IgG) level determination and the impact of hypogammaglobulinemia (HGG) on infections after VAD implantation have not been evaluated before. METHODS: A total of 76 patients (mean age, 53 years) underwent VAD implantation as a bridge to transplantation and had IgG levels determined as a baseline before transplantation. Patients were divided into 2 groups according to IgG level: Control Group (n = 56, IgG > or = 700 mg/dl) and HGG Group (n = 20, IgG < 700 mg/dl). Infection outcome during the VAD course and after transplantation was analyzed in relation to the IgG level. RESULTS: Baseline characteristics were similar in both groups. The incidence of bacteremia (14/20 [70%] vs 18/56 [32%], p = 0.0032) and major infection (19/20 [95%] vs 31/56 [56%], p = 0.0009) were significantly increased in the HGG Group compared with the Control Group. After transplantation, the episodes of rejection were similar in both groups and survival was similar. The HGG Group experienced more cytomegalovirus infections compared with the Control Group (9/20 [45%] vs 9/56 [16%], p = 0.009). CONCLUSIONS: VAD patients with HGG are at increased risk of infections. After transplantation, these patients also experience increased cytomegalovirus infections. A randomized preemptive IgG replacement trial may be warranted in the future to determine if this intervention will alleviate the risk of infection.