Infectious heart disease

2007439 Association between myocardial AD-AMTS-1 expression and myocardial fibrosis in a mu-rine model of viral myocarditis.SHEN E(申锷), etal. Key Lab, Viral Heart Dis, Minist Public Health,Shanghai Cardiovasc Dis Instit, Zhongshan Hosp, FudanUniv, Shanghai 200032. Chin J Cardiol 2007;35(9):854 -858. Objective To investigate the association betweenmyocardial ADAMTS-1 expression and myocardial fibro-sis in coxsackie virus B3( CVB3)-induced acute andchronic murine mycarditis mod…     

Coronary heart disease

2005191 Characteristics of treadmill electrocar-diography and dipyridamole 201T1 myocardial perfu-sion imaging in patients with coronary artery spasm. XIANG Ding-cheng (向定成), et al. Dept Cardiol, Guangzhou Command General Hosp, PLA, Guangzhou 510010. Chin J Nucl Med, 2005; 25(1): 10-13. Objective: To investigate the characteristics of treadmill electrocardiography and dipyridamole 201T1 myocardial perfusion imaging in patients with coronary artery spasm, and to explore a non-invasive pro-     

Can heart rate variation rule out sleep-disordered breathing in heart failure?

In patients with obstructive sleep apnoea (OSA), the very low frequency power spectral density index (VLFI) derived from analysis of heart rate correlates with the severity of obstructive apnoeas. VLFI is also associated with Cheyne-Stokes respiration/central sleep apnoea (CSR/CSA) in congestive heart failure (CHF). The present authors have tested the hypothesis that per cent VLFI, derived from a standard Holter ECG recording, can be used to detect the presence of OSA and CSR/CSA in patients with mild-to-moderate CHF. In total, 60 CHF patients underwent polysomnography with monitoring of heart rate. Data from 33 patients were analysed for per cent VLFI. Of the 60 patients, 27 were excluded due to atrial fibrillation, extensive pacing or frequent ventricular extra systoles. Receiver operator characteristic curves were constructed to establish the per cent VLFI that would optimally identify the presence or absence of sleep-disordered breathing. Using an apnoea-hypopnoea index>20 events.h-1 and setting the per cent VLFI at 2.23% yielded a sensitivity of 85%, specificity of 65%, positive predictive value of 61% and a negative predictive value of 87%. The latter increased to 100% when using an apnoea-hypopnoea cut-off of 30 events.h-1. In conclusion, these results suggest that spectral analysis of heart rate may be useful as a "rule-out test" for sleep-disordered breathing in patients with mild-to-moderate congestive heart failure.     

Displacement of the heart by diaphragm: is this heart alternating?

A-64-year-old man was admitted to the emergency department because of dyspnea. Twelve-lead ECG revealed alternating QRS complexes. In consequence of diagnostic tests, i.e., chest tomography showed eventration of the left diaphragm. In this case, we present an unusual case of electrical alternans due to diaphragmatic eventration.     

Metabolic support for the heart: complementary therapy for heart failure?

The failing heart has an increased metabolic demand and at the same time suffers from impaired energy efficiency, which is a detrimental combination. Therefore, therapies targeting the energy‐deprived failing heart and rewiring cardiac metabolism are of great potential, but are lacking in daily clinical practice. Metabolic impairment in heart failure patients has been well characterized for patients with reduced ejection fraction, and is coming of age in patients with ‘preserved’ ejection fraction. Targeting cardiomyocyte metabolism in heart failure could complement current heart failure treatments that do improve cardiovascular haemodynamics, but not the energetic status of the heart. In this review, we discuss the hallmarks of normal cardiac metabolism, typical metabolic disturbances in heart failure, and past and present therapeutic targets that impact on cardiac metabolism.     

Adult zebrafish heart as a model for human heart? An electrophysiological study

The zebrafish has recently emerged as an excellent model for studies of heart development and regeneration. The physiology of the zebrafish heart has been suggested to resemble that of the human heart in many aspects, whereas, in contrast to mammals, the zebrafish has a remarkable ability to regenerate after heart injury. Thus, zebrafish have been proposed as a cost-effective model for genetic and pharmacological screens of factors affecting heart function and repair. However, realizing the full potential of the zebrafish heart as a model will require a better understanding of the electrophysiology of the adult zebrafish myocardium. Here, we characterize action potentials (APs) from intact adult atria and ventricles and find that the overall shape of zebrafish APs is similar to that of humans. We show that zebrafish, like most mammals, display functional acetylcholine-activated K⁺ channels in the atrium, but not in the ventricle. Furthermore, the zebrafish AP upstroke is dominated by Na⁺ channels, L-type Ca²⁺ channels contribute to the plateau phase and I_Kr channels are involved in repolarization. However, despite these similarities between zebrafish and mammalian electrophysiology, we also identified important differences. In particular, zebrafish display a robust T-type Ca²⁺ current in both atrial and ventricular cardiomyocytes. Interestingly, in most mammals T-type Ca²⁺ channels are only expressed in the developing heart or under pathophysiological conditions, indicating that adult zebrafish cardiomyocytes display a more immature phenotype.     

Misogyny in heart disease?

• Overall, mid‐term outcomes of edge‐to‐edge mitral valve repair with the MitraClip system do not seem to be markedly affected by gender
• Nevertheless, there seems to be subtle differences in the results of men and women treated with MitraClip, which might affect patient selection and therapeutic strategy
• Further studies with larger sample sizes are required to fully assess the potential differences in specific subsets

     

Stem cells for the heart

See related article,pages 101-107.Cardiovascular disease is one of the major health con-cerns of modern societies.In the United States in the year2001 alone,an estimated 64 million people had had one ormore forms of cardiovascular disease,claiming almost onemillion lives,38.5 percent of all deaths(American HeartAssociation).     

Cardiomyocytic apoptosis and heart failure

Heart failure is a major disease seriously threatening human health.Once left ventricular dysfunction develops,cardiac function usually deteriorates and progresses to congestive heart failure in several months or years even if no factors which accelerate the deterioration repeatedly exist.Mechanism through which cardiac function continually deteriorates is still unclear.Cardiomyocytic apoptosis can occur in acute stage of ischemic heart diseases and the compensated stage of cardiac dysfunction.In this review,we summarize recent advances in understanding the role of cardiomyocytic apoptosis in heart failure.     

A heart failure specialist’s perspective on cardiac surgery for heart failure

Aside from cardiac transplantation, ventricular assist devices, and the total artificial heart, cardiac surgery now also plays a major role in the overall management of the heart failure patient. For patients with heart failure, cardiac surgery has steadily moved from being a predominant rescue procedure (eg, aneursymectomy, rupture repair, transplantation) to surgical interventions that can prevent or delay the progression of cardiac dysfunction and failure; these operations now include coronary artery bypass surgery, ventricular restoration, and valvular repair/replacement. This article discusses the role and impact of these specific surgical interventions in the setting of ventricular dysfunction and heart failure.     

Is it possible to operate four heart valves in a patient with heart failure,congenital heart disease and pulmonary hypertension?

We describe a 60-year old man with the history of radical correction of the Tetralogy of Fallot (TOF) in the year 1964. This patient has had a long lasting decompensation of a severe right heart failure with ascites and pulmonary hypertension. On echocardiography he had residual mild pulmonary stenosis (PS) and severe pulmonary and tricuspid regurgitation (TR), moderate aortic and mitral regurgitation. He also had residual ventricular septal defect (VSD) and severe pulmonary hypertension with the maximal gradient on TR 83 mmHg. He was considered unoperable by his cardiologist, however patient decided to undergo a high-risk operation. The operation comprised pulmonary and aortic valve replacement with bioprosthesis, mitral and tricuspid repair, closure of ventricular septal defect, bilateral MAZE and volume reduction of both atria. After a very complicated postoperative course with multiorgan failure he recovered and was discharged home 2 months after operation. The NYHA class improved from IV before operation to II. Twenty months after this operation he experienced infective endocarditis with a leak on the aortic bioprosthesis. He was reoperated with reimplantation of a new aortic bioprosthesis and with a very complicated postoperative course. Sildenafil was added to his therapy due to the persistent severe pulmonary hypertension. He survived and was discharged home.The presented unique high-risk complex reoperation of a congenital heart disease with pulmonary hypertension can be performed only by a very experienced cardiosurgical and cardio-anesthesiological team with a high level of the early and late postoperative care.