Cardiovascular Autonomic Regulation, ETCO2 and the Heart Rate Response to the Tilt Table Test in Patients with Orthostatic Intolerance.

Chronic orthostatic intolerance (COI) is defined by changes in heart rate (HR), blood pressure (BP), respiration, symptoms of cerebral hypoperfusion and sympathetic overactivation. Postural tachycardia syndrome (POTS) is the most common form of COI in young adults and is defined by an orthostatic increase in heart rate (HR) of ≥ 30 bpm in the absence of orthostatic hypotension. However, some patients referred for evaluation of COI symptoms do not meet the orthostatic HR response criterion of POTS despite debilitating symptoms. Such patients are ill defined, posing diagnostic and therapeutic challenges. This study explored the relationship among cardiovascular autonomic control, the orthostatic HR response, EtCO2 and the severity of orthostatic symptoms and fatigue in patients referred for evaluation of COI. Patients (N = 108) performed standardized testing protocol of the Autonomic Reflex Screen and completed the Composite Autonomic Symptom Score (COMPASS-31) and the Fatigue Severity Scale (FSS). Greater severity of COI was associated with younger age, larger phase IV amplitude in the Valsalva maneuver and lower adrenal baroreflex sensitivity. Greater fatigue severity was associated with a larger reduction in ETCO2 during 10 min of head-up tilt (HUT) and reduced low-frequency (LF) power of heart rate variability. This study suggests that hemodynamic changes associated with the baroreflex response and changes in EtCO2 show a stronger association with the severity of orthostatic symptoms and fatigue than the overall orthostatic HR response in patients with COI.

Novel intracoronary supersaturated oxygen treatment for anterior myocardial infarction.

Primary percutaneous coronary intervention (PCI) is now the recommended reperfusion technique for patients with acute ST-segment elevation myocardial infarction. However, despite early reperfusion in the majority of patients, PCI does not achieve effective myocardial reperfusion in a significant proportion of patients due to the prevalence of coronary microvascular obstruction. The amount of infarcted myocardium has been considered to be a reliable indicator of major adverse cardiovascular events and resultant adverse left ventricular remodeling. The purpose of this paper is to review the clinical benefits of supersaturated oxygen therapy following PCI for ST-segment elevation myocardial infarction.

Rare survival of left ventricular free wall rupture following myocardial infarction.

Myocardial free wall rupture is a rare but usually fatal complication of acute myocardial infarction (MI) especially if it occurs out of hospital and occurs in 2-4% of patients who suffer from acute MI. Rapid diagnosis is essential but not always easy as diagnostic tests may be inconclusive. In this case report authors examine a rare and unique patient survival after left ventricular free wall rupture following MI. The patient developed chest pain and hypotension in the hospital and was taken directly to the catheterization laboratory where a diagnostic angiogram showed a high-grade occlusion of a very small marginal branch, fluoroscopy demonstrated a large pericardial effusion, which was drained then auto transfused back to the patient using a femoral vein sheath. Rapid diagnostic testing including transesophageal echocardiography with Definity, transthoracic echocardiography, aortography and left ventriculography were all negative for dissection and rupture. Despite the negative diagnostic test, a high index of suspicion for rupture led to urgent surgical exploration where a large 4-cm hole was found in the lateral wall. Repair was successful and the patient left the hospital about several weeks later.