Arrhythmia occurring as the sole presenting feature in Covid-19

Severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) infection is observed to be associated with several cardiac complications. Cardiac arrhythmias are frequently observed in critically ill patients and are usually associated with myocarditis. We report two patients with Covid-19, in whom serious arrhythmias were the sole presenting feature, in the absence of any of the known manifestations of the disease. Further research is required into this yet unknown mechanism of the effect of Covid-19 on the conduction system. Thus, managing patients with acute-onset arrhythmias of unexplained aetiology, even when they present without known clinical features of Covid-19, should be done with care.

Comparison of three-dimensional echocardiography and speckle tracking echocardiography in quantification and mapping of intraventricular mechanical dyssynchrony

Objectives The aim of the study is to compare two advanced methods of evaluation of left ventricular mechanical dyssynchrony (LVMD), the speckle tracking echocardiography (STE) and the three-dimensional echocardiography (3DE). Methods One hundred thirty-six subjects, with or without LV dysfunction and with or without bundle branch block (BBB), were included in this study, designed to investigate agreement between magnitude and spatial pattern of LVMD as assessed by 3DE and STE. The frequency and severity of LVMD and localization of most asynchronous segments were compared. Results Both 3DE and STE revealed progressive rise in frequency and magnitude of LVMD with increasing disease severity. Dyssynchrony was dependent on left ventricle ejection fraction rather than the QRS duration. The frequency and magnitude of dyssynchrony were maximum in patients having LV dysfunction with left BBB. Compared with STE, 3DE diagnosed LVMD more frequently in patients having LV dysfunction with narrow QRS (17.6% vs 60.3%, respectively; P < 0.001). When the two methods were compared for localization of most asynchronous segments, the results matched only in about 50% cases. Conclusions Both 3DE and STE provided consistent results with progressive rise in magnitude of LVMD, correlating with disease severity. 3DE diagnosed more patients as having LVMD in those having LV dysfunction with narrow QRS. The most delayed segment assessed by two methods matched only in about half the cases. Correlation with clinical CRT responsiveness is needed to conclude which method is more accurate in dyssynchrony mapping for targeted lead placement.

Real-time three-dimensional echocardiographic left heart parameters in healthy indian adults

Objective Cardiac chamber dimensions are race and anthropometry dependent. We determined the age and gender specific 3-Dimensional echocardiographic (3DE) reference values for dimensions and function of left ventricle (LV) and left atrium (LA) in normal Indian adults. Methods This single center prospective study enrolled 133 adult Indians free of heart disease and/or hypertensions, subjecting them to 3DE measurements of left atrial (LA) & left ventricular (LV) volumes, function and left ventricular mass (LVM). The higher limits of normal cut-offs were determined for these parameters and their dependency on age, gender and anthropometry were analyzed. Results The body surface area (BSA) corrected higher limit cut-offs were: 59.37 ml/m2 for LV end diastolic volume (59.19 ml/m2 and 59.61 ml/m2 for men and women, respectively; P = NS); 23.48 ml/m2 for LV end systolic volume (23.27 ml/m2 and 23.11 ml/m2 for men and women, P = NS). Mean LVEF was 64.79% ± 7.26 (62.99% ± 6.51 and 67.05% ± 7.58 in men and women, P = NS). Men had higher LVM than women (119.79 g±23.95 vs. 103.26 g±23.76, P < 0.001), this difference disappeared after BSA indexing. The higher limit cut-offs for normal LA volumes were 20.49 ml for minimum volume (21.18 ml and 19.46 ml for men and women, P = NS) and 39.76 ml for maximum volume (39.60 ml and 40.03 ml in men and women, P = NS). The parameters were smaller compared to western populations but the differences attenuated after BSA indexing. Conclusions The study reports normal 3DE parameters of size and function of left heart chambers in Indians.

Three-dimensional echocardiographic evaluation of mechanical dyssynchrony in systolic heart failure with narrow QRS complex

Objectives To investigate the role of three-dimensional echocardiography (3DE) in evaluation of left ventricular mechanical dyssynchrony (LVMD) in heart failure (HF) patients with narrow QRS. Methods 143 subjects (70 with HF and narrow QRS, 23 with HF and LBBB and 50 controls) were subjected to 3DE, evaluating global and regional dyssynchrony using systolic dyssynchrony index, maximum segmental dyssynchrony and opposite segment dyssynchrony. Spatial distribution of LVMD was studied in each patient using 3DE derived regional time volume curves. Extent of LVMD in HF patients with narrow QRS was compared to those with left bundle branch block (LBBB). Results Frequency of LVMD was similar in HF patients with narrow QRS or LBBB (55.7% vs. 47.8%, p = NS). There was no difference in the severity of LVMD between these two groups (10.7 ± 6.7% vs. 12.1 ± 7.4%, p = NS). Both HF groups had significantly more dyssynchrony than controls. A scattered pattern of distribution of asynchronous segments was seen in narrow QRS patients; 33.96% of them had their earliest contracting segment, instead of delayed segment, located in areas conventionally targeted for LV pacing i.e. anterolateral, inferolateral or inferior segments. Conclusions 3DE confirmed significant dyssynchrony in > 50% HF patients with narrow QRS as demonstrated by other imaging methods. 3D distribution patterns of asynchronous segments indicate possibility of left ventricular mechanics related reasons responsible for lack of CRT responsiveness, an observation that generates hypothesis on possible reasons of CRT non-responsiveness.

Pituitary carcinoid coexisting with systemic lupus erythematosus: A rare combination.

Gastrointestinal carcinoids have occasionally been reported in patients with autoimmune diseases. We report a middle-aged woman who presented with episodic hypertension and a skin rash. Initial evaluation led to the diagnosis of systemic lupus erythematosus for which the patient was treated. Further investigations revealed the presence of a carcinoid tumour in the pituitary. Although gastrointestinal carcinoids associated with autoimmune diseases have been seen occasionally, to our knowledge, extragastric carcinoid coexisting with an autoimmune disorder has never been reported before. A better understanding of how inflammation induces cytological changes leading to development of a carcinoid from a cellular and molecular perspective could provide potential therapeutic strategies for preventing these lesions. Natl Med J India 2016;29:209–11

Bivalirudin: a new promising direct antithrombin.

The deadliest manifestations of ischemic heart disease are initiated and propagated by intra-coronary thrombin generation. Thrombin is resistant to inactivation by heparin when it is bound to fibrin, fibrin degradation products or subendothelial collagen. Recognition of these limitations has led to development of a new class of antithrombin agents which directly target the active sites on the surface of thrombin molecule and are therefore designated as direct antithrombins. These agents do not need mediation of antithrombin III for their action and are not inhibited by platelet factor 4. This report focuses on bivalirudin, a new agent of promising impact on both interventional as well as non-interventional cardiology. It is a short acting anticoagulant which bivalently and directly inhibits thrombin (coagulation factor II). It binds the active (catalytic) site and the fibrinogen-binding site (exosite I). This provides high affinity and specificity for thrombin. Slow cleavage at the Arg3-Pro4 bond results in recovery of thrombin activity after discontinuation of bivalirudin. Bivalirudin inhibits both protease activated receptor 1 and 4 (PAR 1 and PAR 4) thereby effectively inhibiting acute thrombin mediated platelet aggregation. Clinical efficacy has been assessed and proved in over 20 published patient series focussing on patients with acute coronary syndrome with or without myocardial infarction, patients undergoing percutaneous coronary interventions, patients receiving various adjunctive anti-platelet medications, patients with heparin induced thrombocytopenia or patients undergoing cardiac surgery. In contrast to the well established unfractionated heparin, bivalirudin lacks the risk of heparin induced thrombocytopenia. It shows a tendency to lower bleeding risks without reduction of efficacy when compared with the two-pronged treatment with unfractionated heparin and glycoprotein IIb/IIIa inhibitors.