Heart sounds: Past, present, and future from a technological and clinical perspective - a systematic review

The high prevalence of cardiac diseases around the world has created a need for quick, easy and cost effective approaches to diagnose heart disease. The auscultation and interpretation of heart sounds using the stethoscope is relatively inexpensive, requires minimal to advanced training, and is widely available and easily carried by healthcare providers working in urban environments or medically underserved rural areas. Since René-Théophile-Hyacinthe Laennec's simple, monoaural design, the capabilities of modern-day, commercially available stethoscopes and stethoscope systems have radically advanced with the integration of electronic hardware and software tools, however these systems are largely confined to the metropolitan medical centers. The purpose of this paper is to review the history of stethoscopes, compare commercially available stethoscope products and analytical software, and discuss future directions. Our review includes a description of heart sounds and how modern software enables the measurement and analysis of time intervals, teaching auscultation, remote cardiac examination (telemedicine) and, more recently, spectrographic evaluation and electronic storage. The basic methodologies behind modern software algorithms and techniques for heart sound preprocessing, segmentation and classification are described to provide awareness.

Usefulness of acetazolamide in the management of diuretic resistance

Worsening symptoms and fluid overload are the hallmarks of heart failure (HF) decompensation, and fluid removal is central to improvement. Despite high-dose loop diuretics, patients with decompensated HF may develop suboptimal diuresis/diuretic resistance. Sequential nephron blockade with a combination of loop and thiazide/thiazide-like diuretics may be insufficient, resulting in poor outcomes. We present a case wherein urine output improved significantly with acetazolamide. Although the diuretic capacity of acetazolamide is weak on its own, it might be efficient in aiding the efficacy of loop diuretics. We discuss the pathophysiological basis and evidence behind its potential role in diuretic resistance. Drawing from current understanding, we propose a stepwise approach to diuresis in such patients.

To Be or Not To Be: A Case of Recurrent Swelling Syndrome of Thoracic Duct

Thoracic duct aneurysm is a rare entity presenting as a stable, asymptomatic, left supraclavicular swelling. We report an unusual case of a thoracic duct aneurysm in a 71-year-old woman presenting as a recurrent swelling syndrome of the left supraclavicular area associated with sporadic episodes of sharp left subcostal pain. (Level of Difficulty: Intermediate.)

Granulicatella Causing Infective Endocarditis and Glomerulonephritis

Granulicatella is a type of nutritionally variant Streptococcus (NVS) that requires special medium for growth. It has shown to cause infective endocarditis which is associated with higher mortality and complications. We present a case of Granulicatella causing endocarditis and glomerulonephritis. There has only been one such prior case report. An adult male with a remote history of gastric bypass presented with shortness of breath with exertion, lower extremity swelling of 1-month duration. Blood cultures 4/4 bottles grew Granulicatella albicans with infected tooth being the source. Transesophageal echocardiogram revealed a vegetation on the mitral valve. He received intravenous vancomycin. He was found to have acute kidney injury requiring hemodialysis. Kidney biopsy revealed immune complex deposits in the mesangium and along the capillary basement membrane suggestive of post infectious glomerulonephritis. It is crucial to recognize NVS as potential cause for endocarditis in cultures that are slow growing. NVS require a special medium. Though it is rare, NSV can also cause glomerulonephritis. Early recognition is important to help with determining treatment options which may include immunosuppressive therapy along with treatment of underlying infection.