Meenakshi A. Bhalla

Unexplained hypotension: the spectrum of dynamic left ventricular outflow tract obstruction in critical care settings.

Objective:To illustrate the clinical and hemodynamic abnormalities caused by dynamic left ventricular outflow tract obstruction (LVOTO) in critical care setting. Design:We reviewed cases referred to Cardiology with echocardiographic evidence of LVOTO and their clinical presentations. We present those cases where LVOTO can transiently occur without hypertrophic cardiomyopathy when inotropic agents are used for hypotension. Measurements and Main Results:Five women in the 50–70 age range and prior history of hypertension presented with various symptoms like chest discomfort, fatigue, dizziness, atrial fibrillation, and hypotension. An ejection systolic murmur was noted most often in the left third intercostal space and ECG revealed ST-T wave abnormalities. LVOTO caused by mitral systolic anterior motion was detected by echocardiography and catheterization excluded acute coronary disease. In critical care setting, LVOTO can occur due to apical ballooning syndrome, coronary disease, medications, volume depletion, and valvular abnormalities. Because this condition mimics acute coronary syndrome or other etiologies of hypotension in medical and surgical intensive care units, appropriate treatment can be delayed. Nonhypertrophic cardiomyopathy LVOTO usually responds well to fluid replacement, beta blockers, and medication changes. Conclusions:LVOTO should be suspected especially in women presenting with hypotension and systolic murmur in critical care settings. Clinical acumen and timely echocardiography are required to effectively counter this transient but potentially lethal problem.

B-Type Natriuretic Peptide and Impedance Cardiography at the Time of Routine Echocardiography Predict Subsequent Heart Failure Events

BACKGROUNDnDetection of heart failure (HF) in stable outpatients can be difficult until an overt event occurs. This study sought to determine whether the combination of B-type natriuretic peptide (BNP) and impedance cardiography (ICG) could be used in a nonacute clinical setting to risk stratify and predict HF-related events in stable outpatients.nnnMETHODS AND RESULTSnPatients undergoing routine outpatient echocardiography underwent ICG and BNP testing and were followed for one year for HF-related events (Emergency Department [ED] visit or hospitalization due to HF or all-cause death). A total of 524 patients were analyzed, resulting in 57 HF-related events; 16 ED visits, 17 hospitalizations, and 24 all-cause deaths. Using Cox regression analyses, BNP and systolic time ratio index (STRI) by ICG proved to be the strongest predictors of future HF-related events. Patients with a BNP >100 pg/ml and STRI >0.45 sec(-1) had a significantly lower event-free survival rate than those with a high BNP and low STRI (67% versus 89%, P=.001). In patients with LV dysfunction only, if both BNP and STRI values were high, the relative risk of a HF-related event increased by 12.5 (95 % C.I. 4.2-36.7), when compared with patients with a low BNP and low STRI (P<.001).nnnCONCLUSIONSnIn a nonacute clinical setting, both BNP and ICG testing can provide unique predictive power of long-term HF-related events in a stable cohort of patients with and without LV dysfunction.

Evolution of B-type natriuretic peptide in evaluation of intensive care unit shock*

Congestive heart failure (CHF) is a major and increasing cause of death and disability in United States. Its prevalence is attributable to the drastic increase in cardiovascular risk factors such as obesity and diabetes and improved survival rate after acute myocardial infarction (and subsequent dev