Faisal F. Syed

Characteristics of premature ventricular complexes as correlates of reduced left ventricular systolic function: study of the burden, duration, coupling interval, morphology and site of origin of PVCs.

PVCs and Left Ventricular Dysfunction. Background: Frequent premature ventricular complexes (PVCs) can cause a decline in left ventricular ejection fraction (LVEF). We investigated whether the site of origin and other PVC characteristics are associated with LVEF.

Predominance of interleukin-22 over interleukin-17 at the site of disease in human tuberculosis

Summary The inflammatory response to Mycobacterium tuberculosis (M.tb) at the site of disease is Th1 driven. Whether the Th17 cytokines, IL-17 and IL-22, contribute to this response in humans is unknown. We hypothesized that IL-17 and IL-22 contribute to the inflammatory response in pleural and pericardial disease sites of human tuberculosis (TB). We studied pleural and pericardial effusions, established TB disease sites, from HIV-uninfected TB patients. Levels of soluble cytokines were measured by ELISA and MMP-9 by luminex. Bronchoalveolar lavage or pericardial mycobacteria-specific T cell cytokine expression was analyzed by intracellular cytokine staining. IL-17 was not abundant in pleural or pericardial fluid. IL-17 expression by mycobacteria-specific disease site T cells was not detected in healthy, M.tb-infected persons, or patients with TB pericarditis. These data do not support a major role for IL-17 at established TB disease sites in humans. IL-22 was readily detected in fluid from both disease sites. These IL-22 levels exceeded matching peripheral blood levels. Further, IL-22 levels in pericardial fluid correlated positively with MMP-9, an enzyme known to degrade the pulmonary extracellular matrix. We propose that our findings support a role for IL-22 in TB-induced pathology or the resulting repair process.

Correlative anatomy for the electrophysiologist, part II: cardiac ganglia, phrenic nerve, coronary venous system.

Cardiac Ganglia, Phrenic Nerve, Coronary Venous System. There is an increasing need for invasive electrophysiologists to appreciate the exact anatomy of the epicardial space and the coronary veins. The location of the epicardial fat, the complementary relationship with the main cardiac veins, and the location of sensitive structures (arteries, phrenic nerve, esophagus) have become required knowledge for electrophysiologists, and accessing the epicardial space with this thorough knowledge of the pericardial sinuses and recesses is essential to allow radiographic correlation during catheter manipulation. In this review, we briefly describe the anatomy of the pericardial space and then discuss the specific correlation for the invasive electrophysiologist, highlighting epicardial access, catheter navigation, and avoidance of collateral injury, with specific attention to the important recesses of the pericardial space, their regional anatomy, and radiographic correlation when navigating catheters to these locations. We also discuss the anatomy of the main cardiac veins in the context of catheter mapping and ablation of the epicardial substrate through the venous system and without subxiphoid pericardial access. In part II of this series we discuss the detailed regional anatomy of the cardiac ganglia, phrenic nerve, and coronary venous system. (J Cardiovasc Electrophysiol, Vol. 22, pp. 104‐110, January 2011)

The Presence of Lys27 Instead of Asn27 in Human Phospholamban Promotes Sarcoplasmic Reticulum Ca2+-ATPase Superinhibition and Cardiac Remodeling

Background— Phospholamban (PLN) is an inhibitor of the Ca2+ affinity of sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA2). The amino acid sequence of PLN is highly conserved, and although all species contain asparagine (Asn), human PLN is unique in containing lysine (Lys) at amino acid 27. Methods and Results— Human PLN was introduced in the null background. Expression of human PLN, at similar levels to mouse wild-type PLN, resulted in significant decreases in the affinity of SERCA2 for Ca2+, attributed to unique spatial conformation of this PLN form and increases in its monomeric active unit compared with mouse PLN. The increased inhibition by human PLN was associated with attenuated cardiac contractility in the intact-animal, organ, and cardiomyocyte levels and with depressed calcium kinetics. These inhibitory effects could not be fully reversed even on maximal isoproterenol stimulation. There were no alterations in the expression levels of SERCA2, calsequestrin, ryanodine receptor, and FKBP12, although the sodium/calcium exchanger and the L-type Ca2+ channel expression levels were upregulated. The depressed function resulted in increased heart/body weight ratios and phosphorylation levels of Akt, p38, and Erk1/2. Conclusions— Human PLN may play a more inhibitory role than that of other species in Ca2+ cycling. Expression of human PLN in the mouse is compensated by alterations in Ca2+-handling proteins and cardiac remodeling in an effort to normalize cardiac contractility. Thus, the unique amino acid sequence of human PLN may be critical in maintaining a high cardiac reserve, which is of paramount importance in the regulation of human cardiac function.

Constrictive pericarditis--a curable diastolic heart failure.

Constrictive pericarditis can result from a stiff pericardium that prevents satisfactory diastolic filling. The distinction between constrictive pericarditis and other causes of heart failure, such as restrictive cardiomyopathy, is important because pericardiectomy can cure constrictive pericarditis. Diagnosis of constrictive pericarditis is based on characteristic haemodynamic and anatomical features determined using echocardiography, cardiac catheterization, cardiac MRI, and CT. The Mayo Clinic echocardiography and cardiac catheterization haemodynamic diagnostic criteria for constrictive pericarditis are based on the unique features of ventricular interdependence and dissociation of intrathoracic and intracardiac pressures seen when the pericardium is constricted. A complete pericardiectomy can restore satisfactory diastolic filling by removing the constrictive pericardium in patients with constrictive pericarditis. However, if inflammation of the pericardium is the predominant constrictive mechanism, anti-inflammatory therapy might alleviate this transient condition without a need for surgery. Early diagnosis of constrictive pericarditis is, therefore, of paramount clinical importance. An improved understanding of how constrictive pericarditis develops after an initiating event is critical to prevent this diastolic heart failure. In this Review, we discuss the aetiology, pathophysiology, and diagnosis of constrictive pericarditis, with a specific emphasis on how to differentiate this disease from conditions with similar clinical presentations.Constrictive pericarditis can result from a stiff pericardium that prevents satisfactory diastolic filling. The distinction between constrictive pericarditis and other causes of heart failure, such as restrictive cardiomyopathy, is important because pericardiectomy can cure constrictive pericarditis. Diagnosis of constrictive pericarditis is based on characteristic haemodynamic and anatomical features determined using echocardiography, cardiac catheterization, cardiac MRI, and CT. The Mayo Clinic echocardiography and cardiac catheterization haemodynamic diagnostic criteria for constrictive pericarditis are based on the unique features of ventricular interdependence and dissociation of intrathoracic and intracardiac pressures seen when the pericardium is constricted. A complete pericardiectomy can restore satisfactory diastolic filling by removing the constrictive pericardium in patients with constrictive pericarditis. However, if inflammation of the pericardium is the predominant constrictive mechanism, anti-inflammatory therapy might alleviate this transient condition without a need for surgery. Early diagnosis of constrictive pericarditis is, therefore, of paramount clinical importance. An improved understanding of how constrictive pericarditis develops after an initiating event is critical to prevent this diastolic heart failure. In this Review, we discuss the aetiology, pathophysiology, and diagnosis of constrictive pericarditis, with a specific emphasis on how to differentiate this disease from conditions with similar clinical presentations.

Effusive-constrictive pericarditis

Effusive-constrictive pericarditis (ECP) is an increasingly recognized clinical syndrome. It has been best characterized in patients with tamponade who continue to have elevated intracardiac pressure after the removal of pericardial fluid. The disorder is due to pericardial inflammation causing constriction in conjunction with the presence of pericardial fluid under pressure. The etiology is diverse with similar causes to constrictive pericarditis and the condition is more prevalent with certain etiologies such as tuberculous pericarditis. The diagnosis is most accurately made using simultaneous intrapericardial and right atrial pressure measurements with pericardiocentesis, although non-invasive Doppler hemodynamic assessment can assess residual hemodynamic findings of constriction following pericardiocentesis. The clinical presentation has considerable overlap with other pericardial syndromes and as yet there are no biomarkers or non-invasive findings that can accurately predict the condition. Identifying patients with ECP therefore requires a certain index of clinical suspicion at the outset, and in practice, a proportion of patients may be identified once there is objective evidence for persistent atrial pressure elevation after pericardiocentesis. Although a significant number of patients will require pericardiectomy, a proportion of patients have a predominantly inflammatory and reversible pericardial reaction and may improve with the treatment of the underlying cause and the use of anti-inflammatory medications. Patients should therefore be observed for the improvement on these treatments for a period, whenever possible, before advocating pericardiectomy. Imaging modalities identifying ongoing pericardial inflammation such as contrast-enhanced magnetic resonance imaging or nuclear imaging may identify those subsets more likely to respond to medical therapies. Pericardiectomy, if necessary, requires removal of the visceral pericardium.

Recent advances in HIV-associated cardiovascular diseases in Africa

The last decade has witnessed major advances in our understanding of the epidemiology and pathophysiology of HIV-related cardiovascular disease in sub-Saharan Africa. In this review, we summarise these and discuss clinically relevant advances in diagnosis and treatment. In the Heart of Soweto Study, 10% of patients with newly diagnosed cardiovascular disease were HIV positive, and the most common HIV-related presentations were cardiomyopathy (38%), pericardial disease (13%) and pulmonary arterial hypertension (8%). HIV-related cardiomyopathy is more common with increased immunosuppression and HIV viraemia. With adequate antiretroviral therapy, the prevalence is low. Contributing factors such as malnutrition and genetic predisposition are under investigation. In other settings, pericardial disease is the most common presentation of HIV-related cardiovascular disease (over 40%), and over 90% of pericardial effusions are due to Mycobacterium tuberculosis (TB) pericarditis. HIV-associated TB pericarditis is associated with a greater prevalence of myopericarditis, a lower rate of progression to constriction, and markedly increased mortality. The role of steroids is currently under investigation in the form of a randomised controlled trial. HIV-associated pulmonary hypertension is significantly more common in sub-Saharan Africa than in developed countries, possibly as a result of interactions between HIV and other infectious agents, with very limited treatment options. It has recently been recognised that patients with HIV are at increased risk of sudden death. Infection with HIV is independently associated with QT prolongation, which is more marked with hepatitis C co-infection and associated with a 4.5-fold higher than expected rate of sudden death. The contribution of coronary disease to the overall burden of HIV-associated cardiovascular disease is still low in sub-Saharan Africa.

HIV-1 infection alters CD4+ memory T-cell phenotype at the site of disease in extrapulmonary tuberculosis

HIV‐1‐infected people have an increased risk of developing extrapulmonary tuberculosis (TB), the immunopathogenesis of which is poorly understood. Here, we conducted a detailed immunological analysis of human pericardial TB, to determine the effect of HIV‐1 co‐infection on the phenotype of Mycobacterium tuberculosis (MTB)‐specific memory T cells and the role of polyfunctional T cells at the disease site, using cells from pericardial fluid and blood of 74 patients with (n=50) and without (n=24) HIV‐1 co‐infection. The MTB antigen‐induced IFN‐γ response was elevated at the disease site, irrespective of HIV‐1 status or antigenic stimulant. However, the IFN‐γ ELISpot showed no clear evidence of increased numbers of antigen‐specific cells at the disease site except for ESAT‐6 in HIV‐1 uninfected individuals (p=0.009). Flow cytometric analysis showed that CD4+ memory T cells in the pericardial fluid of HIV‐1‐infected patients were of a less differentiated phenotype, with the presence of polyfunctional CD4+ T cells expressing TNF, IL‐2 and IFN‐γ. These results indicate that HIV‐1 infection results in altered phenotype and function of MTB‐specific CD4+ T cells at the disease site, which may contribute to the increased risk of developing TB at all stages of HIV‐1 infection.

Correlative anatomy for the electrophysiologist, part I: The pericardial space, oblique sinus, transverse sinus

The Pericardial Space, Oblique Sinus, Transverse Sinus. There is an increasing need for invasive electrophysiologists to appreciate the exact anatomy of the epicardial space and the coronary veins. The location of the epicardial fat, the complementary relationship with the main cardiac veins, and the location of sensitive structures (arteries, phrenic nerve, esophagus) have become required knowledge for electrophysiologists, and accessing the epicardial space with this thorough knowledge of the pericardial sinuses and recesses is essential to allow radiographic correlation during catheter manipulation. In this review, we briefly describe the anatomy of the pericardial space and then discuss the specific correlation for the invasive electrophysiologist, highlighting epicardial access, catheter navigation, and avoidance of collateral injury with specific attention to the important recesses of the pericardial space, their regional anatomy, and radiographic correlation when navigating catheters to these locations. We also discuss the anatomy of the main cardiac veins in the context of catheter mapping and ablation of the epicardial substrate through the venous system and without subxiphoid pericardial access. In Part I of this two‐part series, we discuss the regional anatomy of the pericardial space, oblique sinus, and transverse sinus. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1421‐1426, December 2010)

Prevalence, Hemodynamics, and Cytokine Profile of Effusive-Constrictive Pericarditis in Patients with Tuberculous Pericardial Effusion

Background Effusive constrictive pericarditis (ECP) is visceral constriction in conjunction with compressive pericardial effusion. The prevalence of proven tuberculous ECP is unknown. Whilst ECP is distinguished from effusive disease on hemodynamic grounds, it is unknown whether effusive-constrictive physiology has a distinct cytokine profile. We conducted a prospective study of prevalence and cytokine profile of effusive-constrictive disease in patients with tuberculous pericardial effusion. Methods From July 2006 through July 2009, the prevalence of ECP and serum and pericardial levels of inflammatory cytokines were determined in adults with tuberculous pericardial effusion. The diagnosis of ECP was made by combined pericardiocentesis and cardiac catheterization. Results Of 91 patients evaluated, 68 had tuberculous pericarditis. The 36/68 patients (52.9%; 95% confidence interval [CI]: 41.2-65.4) with ECP were younger (29 versus 37 years, P=0.02), had a higher pre-pericardiocentesis right atrial pressure (17.0 versus 10.0 mmHg, P<0.0001), serum concentration of interleukin-10 (IL-10) (38.5 versus 0.2 pg/ml, P<0.001) and transforming growth factor-beta (121.5 versus 29.1 pg/ml, P=0.02), pericardial concentration of IL-10 (84.7 versus 20.4 pg/ml, P=0.006) and interferon-gamma (2,568.0 versus 906.6 pg/ml, P=0.03) than effusive non-constrictive cases. In multivariable regression analysis, right atrial pressure > 15 mmHg (odds ratio [OR] = 48, 95%CI: 8.7-265; P<0.0001) and IL-10 > 200 pg/ml (OR=10, 95%CI: 1.1, 93; P=0.04) were independently associated with ECP. Conclusion Effusive-constrictive disease occurs in half of cases of tuberculous pericardial effusion, and is characterized by greater elevation in the pre-pericardiocentesis right atrial pressure and pericardial and serum IL-10 levels compared to patients with effusive non-constrictive tuberculous pericarditis.