Pitfalls of AHI system of severity grading in obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is the major underlying co-morbidity in many of the non-communicable diseases (NCD) due to obesity as a common risk factor. Incidence and prevalence of OSA is on the constant rise ever since this entity came to forefront three decades ago. Precise treatment of underlying OSA is extremely important in major NCDs like diabetes mellitus, hypertension, endocrine disorders and vascular diseases. OSA is subcategorized in to mild, moderate and severe based of apnoea-hypopnea index (AHI). Based on the severity grading, treatment of OSA ranges from life style modifications to oral appliances, continuous positive airway pressure (CPAP) and surgeries. AHI system of severity grading in OSA has several inherent shortcomings and using AHI system for severity grading as the holy grail is likely to be counter-productive. AHI system equates apnoea and hypopnea as equal events, whereas physiological effects vary significantly. AHI system does not account duration of apnoea or body position during apnoeic events. We discuss at length the pitfalls of AHI system of severity grading in OSA.

Right ventricular outflow obstruction caused by cocoon duct occluder used for closure of ruptured sinus of valsalva aneurysm.

Hemolytic anemia and right ventricular outflow tract obstruction following device closure of ruptured sinus of Valsalva have seldom been reported in isolated case reports, and exact incidence is not known. A gentleman presented with severe delayed hemolytic anemia following the use of cocoon duct occluder for ruptured sinus of Valsalva. Right ventricular outflow tract obstruction of unclear etiology was also reported on transthoracic echocardiography, necessitating retrieval of the device and surgical closure of the defect. Intraoperative transesophageal echocardiography (TEE) showed right ventricular outflow obstruction by the cocoon device itself with a normal pulmonary valve. In this report, we emphasize that improper device selection for closure of ruptured sinus of Valsalva aneurysm, may lead to delayed leaks across the device, which can gradually progress causing hemolytic anemia and high gradient across the right ventricular outflow tract. Intraoperative TEE helped to delineate the cause of right ventricular outflow tract obstruction.

Refractory hypokalemia while weaning off bypass.

Hypokalemia is defined as serum potassium level less than 3.5 mEq/L. When the serum level of potassium is less than 3 mEq/L, intravenous potassium supplementation is warranted. A 23 yr old adult female with complaints of dyspnoea (NYHA II) since 6 yrs, dyspnoea (NYHA III) and paroxysmal nocturnal dyspnoea on and off since 2 months, diagnosed with severe mitral stenosis, was posted for mitral valve replacement. After the release of ACC, ECG revealed sine wave pattern, Transesophageal echocardiographic examination revealed global hypokinesia and ABG showed potassium of 2.3 mEq/L. Hypokalemia in cardiac patients can occur due to the effect of poor oral intake, increased renal loss by the secondary hyperaldosteronism in congestive heart failure, loss due to use of digoxin and diuretics like thiazide diuretics, loop diuretics etc. Hypokalemia should be avoided while weaning off cardiopulmonary support as it can lead to atrial and ventricular arrhythmias. Potassium ion is very important for the normal contractility of the heart. Hypokalemia if refractory to intravenous potassium supplementation, concomitant magnesium deficiency should be suspected and treated.

Unknown left atrial appendage mass! real-time three-dimensional transesophageal echocardiography helps in identification.

Left Atrial Appendage (LAA) is the most contractile part of Left atrium. It is also the most frequent place for thrombus formation that may lead to disastrous consequences. Complete trasoesophageal echocardiography examination always includes assessing LAA but sometimes unusually placed pectinate muscle, which is a normal structure may give baffling shadow that can only be interpreted correctly by Real time 3D echocardiography.

In response to: Unsolved enigma of atrial myxoma with biventricular dysfunction.

Thanks to Raut et al.[1] for appreciating our efforts in managing the case of biatrial myxomas. A brief discussion is warranted here on the types, size of cardiac myxomas, interleukin 6 (IL-6) levels, left ventricle (LV) dysfunction, and their relation. IL-6 is a pleiotropic cytokine with a variety of biologic activities, including differentiation of B cell, thymocytes, and T cells; activation of macrophages; and stimulation of hepatocyte to produce acute-phase proteins such as C-reactive protein.[2],[3] It is also said to have paracrine, endocrine, and autocrine growth functions.[3].

Atrial myxomas causing severe left and right ventricular dysfunction.

Myxomas are the most common cardiac tumors, accounting for about 50% of benign primary cardiac tumors, with the majority located in the left atrium, and 80% of which originate in the interatrial septum. We report two cases with severe cachexia, neurological sequelae, and severe biventricle dysfunction secondary to atrial myxomas with marked early improvement after tumor excision.