Correlation of Electric Cardiometry and Continuous Thermodilution Cardiac Output Monitoring Systems

Purpose: Impedance Cardiography (ICG) with its drawbacks to reliably estimate cardiac output (CO) when compared to reference methods has led to the development of a novel technique called Electrical Cardiometry (EC). The purpose of this study was to compare EC-CO with the Continuous CO (CCO) derived from Pulmonary Artery Catheter (PAC). Methods: 60 patients scheduled to undergo coronary artery surgery necessitating the placement of PAC were studied in the operating room. Standard ECG electrodes were used for EC-CO measurements. Simultaneous CO measurement from EC and PAC was done at three predefined time points and were correlated. Results: A significant high correlation was found between the EC-CO and CCO at the three time points. Bland and Altman analysis revealed a bias of 0.08 L/min, a precision of 0.15 L/min, with a narrow limit of agreement (-0.13 to 0.28 L/min). The percentage error between the methods was 3.59%. Conclusion: The agreement between EC-CO and CCO is clinically acceptable and these two techniques can be used interchangeably. Mediastinal opening has no effect on the correlation between these two modalities.

Severe Mitral Regurgitation Due to Pacing in Patient Post Aortic Valve Replacement (A Case Report)

Epicardial Cardiac pacing may lead to severe Mitral Regurgitation by one of the following mechanisms: 1) Inappropriate Atrioventricular interval. 2) Myocardial ischemia due to fast heart rate may cause transient papillary muscle dysfunction. 3) Right Ventricular apical pacing may lead to Left Ventricular dyssynchrony in the presence of optimal Atrioventricular synchrony. Acute severe Mitral Regurgitation leading to acute severe hemodynamic deterioration is a reported complication of Permanent Pacemaker insertion. Our case demonstrated acute severe MR as a consequence of RV Pacing leading to acute hemodynamic deterioration, which was relieved on withdrawal of pacing. Left Ventricular dyssynchrony can be relieved by reducing the peacemaker rate or changing to biventricular pacing, this reduces the severity of Mitral Regurgitation and improves the hemodynamics due to simultaneous activation of left and right ventricles. This case illustrates the acute and potentially dramatic effects of intra-Left Ventricular dyssynchrony upon Mitral Valve function. Informed consent was obtained from the patient to report the case. Thus right ventricular pacing can cause left ventricular dyssynchrony leading to worsening of Mitral Regurgitation. It is important to pay attention to mode of pacing when evaluating Mitral Regurgitation in patients with Right Ventricular pacemaker and unstable hemodynamics after initiation of pacing.

Tracing the failing heart: dual genetic fate mapping for target identification

In a recent study published in Nature Genetics,1 Han and colleagues employed a dual genetic lineage tracing approach in combination with a model of heart failure(HF)to identify a key sub-population of endocardium-derived fibroblasts,which gives rise to excessive myofibroblast formation in a Wnt pathway-mediated manner and contributes to cardiac fibrosis.1 The identified fibroblast sub-population and Wnt signaling pathway could be novel targets for the therapy of HF.Improvements in risk management and cardiovascular inter-vention have significantly reduced age-specific cardiovascular disease-related mortality.In contrast,the rate of HF-related hospitalisations has increased over the past decades and HF is a disease with highest social and economic cost in industrialized countries.HF is defined as impairment of the heart’s blood pumping function and its severity is assessed based on ejection fraction.HF often occurs after myocardial infarction(MI),with infarct size and quality of ventricular remodeling after MI influencing ventricular dysfunctions.Causes of HF also include hypertension,atrial fibrillation,and cardiomyopathies(Fig.1).Especially elderly patients with recurrent MI and comorbidities are increasingly presenting with signs of HF.

Anesthesia for pregnant women with Mitral stenosis

Background Rheumatic heart disease is still a major heart problem associated with pregnancy in south China, despite its declining trend. The mortality and morbidity are considerably reduced1 by better perinatal care, where the anesthesiologist plays a major role in the multidisciplinary approach. Nevertheless, in wealthy nation, rheumatic disease has become uncommon and complex congenital heart disease is increasing in the recent decades. With the advent of intensive obstetric and anesthetic care, the death rate of pregnant women with heart disease is lower in mitral stenosis compared with other congenital heart diseases like Eisenmenger＇s syndrome, pulmonary vascular obstructive disease and Marfan＇s syndrome with aortopathy2. Although mitral stenosis is often associated with mitral regurgitation, morbidity is usually related to mitral stenosis3.