The Relevance of Preventive Implantable Cardioverter-Defibrillators (ICDs) in Non-Ischemic Cardiomyopathy in the Presence of Effective Quadruple Therapy for Heart Failure: A Review of Contemporary Medical Literature.

Cardiomyopathy is a disease of the cardiomyocytes that affects their structural function, leading to heart failure (HF). Non-ischemic cardiomyopathy (NICM) includes a subtype of dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), and hypertrophic cardiomyopathy (HCM). These types of cardiomyopathies have no coronary artery vessel involvement. The most common cause of NICM is DCM. In the ischemic cardiomyopathy (ICM) subtype, the utilization of implantable cardioverter-defibrillators (ICDs) has been effective in the prevention of sudden cardiac death (SCD). However, the relevance of ICDs in patients with NICM having an ejection fraction (EF) ≤35%, who are also receiving effective quadruple therapy (i.e., angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter-2 (SGLT2) inhibitors) for HF has been a topic of debate. The purpose of this review is to analyze the benefits of preventive ICDs in NICM patients on adequate quadruple therapy for HF. The current guidelines recommend ICD implantation in patients with NICM who have a left ventricular ejection fraction of ≤35%, come under the New York Heart Association (NYHA) class II or III, and are in sinus rhythm with optimal medical therapy. The evidence supporting this recommendation is limited. Numerous clinical studies and meta-analyses have been conducted to look into this issue. While some have discovered a substantial decrease in mortality with the implantation of an ICD in patients with NICM, others have not found significant changes. Thereby, further investigations are required to define the function of ICDs in this population.

Fine structural characterisation of a Rickettsia-like organism in human platelets from patients with symptoms of ehrlichiosis.

Since 1982, Ehrlichia platys infection has been diagnosed in canines from Venezuela by the use of buffy coat smears. In 1992, ehrlichia-like bodies were observed in platelets from a severely ill girl by light microscopy. The patient was seropositive to E. chaffeensis by the indirect fluorescent antibody test (IFAT). Tetracycline was administered and the patient recovered. More than 400 cases with such intra-platelet organisms have been studied at this laboratory over the past 6 years, and all the patients had a good response to the treatment. To determine whether the organisms in human blood platelets were truly platelet ehrlichiae, IFAT and transmission electron microscopy (TEM) studies were undertaken in four patients. Light microscopic examination of blood samples revealed the dense organism inside platelets, and a great reactivity of the blood cells. Sera from the four patients were seronegative against E. chaffeensis and E. platys antigens. Three of four samples contained the intra-platelet organisms when examined by TEM. Electron microscopy showed platelets with vacuoles containing pleomorphic organisms. These organisms had a thickened membrane, an electron-translucent inner area and an electron-dense granular component in the periphery. An abundant electron-dense material was observed surrounding them. The ultrastructure of such micro-organisms has not been reported previously, Based on the similarity of many of their characteristics with rickettsiae, we suggest that the microorganisms found in the present study might belong to the family Rickettsiaceae.