Stress Cardiomyopathy Caused by Diving: Case Report and Review of the Literature.

BACKGROUND: Stress cardiomyopathy is characterized by transient myocardial dysfunction that mimics a myocardial infarction in the absence of obstructive coronary artery disease. The onset is frequently triggered by an acute illness or intense physical or emotional stress. CASE REPORT: We describe the case of a 47-year-old woman who was brought to the emergency department with acute onset shortness of breath while scuba diving. She was found to have acute pulmonary edema radiographically. Her troponins were noted to be positive. Initial echocardiogram showed basal hypokinesis with hyperkinesis of apex. She was treated with noninvasive ventilation and intravenous diuretic therapy and her symptoms significantly improved. She subsequently underwent cardiac catheterization which revealed nonobstructive coronary artery disease. An exercise stress echocardiogram was performed 2 days later that revealed resolution of the wall motion abnormality and no ischemia at high levels of exercise. A diagnosis of reverse stress (Takotsubo) cardiomyopathy was made based on Mayo Clinic Diagnostic criteria. ​WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case brings to light the risk of stress cardiomyopathy in divers. The diagnosis should be considered in patients presenting with acute pulmonary edema during diving.

Does risk for major adverse cardiac events in patients undergoing vasodilator stress with adjunctive exercise differ from patients undergoing either standard exercise or vasodilator stress with myocardial perfusion imaging?

BACKGROUND: In patients with functional limitations, the use of adjunctive exercise with vasodilator stress has advantages over vasodilator stress alone in single photon emission computed tomography myocardial perfusion imaging (MPI) for technical reasons and with regards to more effective cardiac risk stratification. Whether patients who undergo vasodilator with adjunctive exercise stress MPI possess clinical characteristics and cardiac risk that differs from those who undergo standard exercise or vasodilator stress MPI is unknown. METHODS: Prospectively collected data on 19,367 consecutive patients referred for stress MPI to a tertiary care center (9,331 [48%] underwent exercise-only, 3,793 [20%] underwent vasodilator plus exercise, and 6,243 [32%] underwent vasodilator-only) were analyzed. Perfusion data were scored using the ASNC 17-segment with a summed stress score (SSS) < 4 = normal, 4-8 = mildly abnormal, and > 8 = moderate to severely abnormal. Patients were followed a mean of 1.96 ± 0.95 years. Demographics, clinical characteristics, and the occurrence of major adverse cardiac events (cardiac death or nonfatal myocardial infarction) were compared between the three stress modality groups. RESULTS: Comparison of demographics and clinical characteristics revealed significant differences in gender, age, cardiac risk factors, and stress MPI between the three stress modality groups (P < .001). In follow-up, cardiac event-free survival of patients in the vasodilator plus exercise stress group was significantly higher than those in the vasodilator-only group but lower than those in the exercise-only group (P < .001). Annualized cardiac event rates of patients in the vasodilator plus exercise stress group were significantly lower than those in the vasodilator-only group for all three categories of the SSS (P < .001). After multivariable adjustment, with exercise-only as reference category, vasodilator plus exercise and vasodilator-only stress emerged as independent predictors (more likely occurrence) of cardiac death, while vasodilator-only stress emerged as an independent predictor (more likely occurrence) of cardiac death or nonfatal myocardial infarction. With vasodilator-only as the reference category, exercise-only and vasodilator plus exercise stress emerged as independent predictors (less likely occurrence) of cardiac death as well as of cardiac death or nonfatal myocardial infarction. CONCLUSIONS: Patients undergoing vasodilator plus exercise stress MPI possess clinical characteristics and cardiac risk that differs significantly from those undergoing either standard exercise or vasodilator stress MPI and places them in a lower risk category compared to vasodilator stress alone.

Central line associated blood stream infection related to cooling catheter in cardiac arrest survivors undergoing therapeutic hypothermia by endovascular cooling.

INTRODUCTION: The risk of central line associated blood stream infections (CLABSI) related to cooling catheters used for therapeutic hypothermia (TH) is unclear. METHODS: We performed a retrospective analysis on 131 cardiac arrest survivors between 2007 and 2010, who underwent TH by femorally placed endovascular cooling catheter. All patients received prophylactic intravenous ampicillin-sulbactam for 72 hours to reduce the risk of aspiration pneumonia. Cooling catheter related CLABSI and other infections over a period of seven days from initiation of TH were estimated. RESULTS: Of a total 131 patients, 16 (12%) patients had bacteremia or infection prior to initiation of TH and were excluded. Of the remaining 115 (88%) patients, zero (0%) patients had cooling catheter related CLABSI and 23 (20%) patients had other infections during the study period. CONCLUSION: In cardiac arrest survivors undergoing TH, femorally placed endovascular cooling catheter is not associated with an increased incidence of CLABSI.

Does location matter? Prognostic value of single-photon emission computed tomography myocardial perfusion imaging by vascular territory.

BACKGROUND: The location of a myocardial perfusion abnormality frequently affects clinical decision making, especially if the left anterior descending artery (LAD) territory is involved. The purpose of this study was to determine whether the location of abnormalities on single-photon emission computed tomography (SPECT) imaging affects outcomes. METHODS: We retrospectively analyzed 21,294 consecutive patients with known or suspected coronary artery disease who underwent exercise or pharmacological stress SPECT over a 10-year period. Using the ASNC 17-segment model, 2 observers interpreted images with regards to defect severity, size, and reversibility. The summed stress score (SSS) was used in relation to vascular territories [LAD, right coronary artery (RCA), and left circumflex artery (LCx)]. All patients were followed over a mean period of 2.5 ± 2 years for cardiac events (cardiac death or non-fatal myocardial infarction). RESULTS: Of the enrolled patients, 5,676 had single-vessel territory defects with a mean SSS of 4.3 ± 2.8. Cardiac event-free survival curves revealed no significant difference between the 3 locations (LAD, RCA, and LCx) (P = .235). When compared by mild (2-3), moderate (4-8), or severe (>8) SSS, outcomes between the 3 groups were again similar. There were 2,907 patients with two-vessel territory defects with a mean SSS of 10.8. Outcomes were similar between the following 2 groups: two-vessel with LAD involvement and two-vessel without LAD involvement (P = .558). CONCLUSION: In patients with single- or two-vessel territory perfusion abnormalities with similar size and severity of perfusion defects, the location of defect did not impact future cardiac events. Location of myocardial perfusion defect on SPECT imaging may not be helpful in clinical decision making.

The clinical value of single photon emission computed tomography myocardial perfusion imaging in cardiac risk stratification of very elderly patients (≥80 years) with suspected coronary artery disease.

BACKGROUND: The role of single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) in cardiac evaluation of the very elderly patients is unclear. We investigated the clinical value of SPECT MPI in very elderly patients (≥80 years) with suspected coronary artery disease (CAD) as well as in comparison to younger patients. METHODS AND RESULTS: A retrospective analysis of prospectively collected data from 8,864 patients [1,093 patients ≥80 years (very elderly), 3,369 patients 65-79 years (elderly), and 4,402 patients 50-64 years (middle-aged)] with suspected CAD who underwent exercise and/or pharmacologic stress testing with SPECT MPI between 1996 and 2005 was performed. Clinical and SPECT MPI characteristics, cardiac event rates, early (≤60 days) cardiac catheterization and revascularization rates of very elderly patients were compared to that of younger patients. Mean follow-up for cardiac events (cardiac death or non-fatal myocardial infarction) was 1.9 ± 0.9 years. Very elderly patients with moderate to severely abnormal SSS had a significantly higher annualized cardiac event rate than those with mildly abnormal or normal study (9.6% vs 3.4% and 2.5% respectively, P < .001). Across all categories of SSS, very elderly patients had a significantly higher cardiac event rate as compared to younger patients (P < .001). Early cardiac catheterization and revascularization referrals in very elderly patients increased as a function of severity of ischemia on SPECT MPI (P < .001), although these referral rates were significantly lower in very elderly patients with mild to moderate and severe ischemia as compared to younger patients (P < .05). CONCLUSIONS: In very elderly patients (≥80 years) with suspected CAD, SPECT MPI has prognostic and incremental value in the noninvasive cardiovascular assessment for risk stratification and may influence medical decisions.

Utilization of bedside ultrasound in the diagnosis and management of massive pulmonary embolism: a case report.

The prompt diagnosis and treatment of massive pulmonary embolism is a well-known challenge for physicians. We report a case of a 61-year-old hemodynamically unstable man who presented to the emergency department with complaints of acute dyspnea. After performing a focused history and physical, we used bedside ultrasound to diagnose significant right heart strain, which suggested massive bilateral pulmonary embolisms. This diagnosis was further supported by the visualization of deep venous thrombosis in the left lower extremity. The patient was treated with IV tissue plasminogen activator in the emergency department and survived to discharge in his usual state of health.

The occurrence of shivering in cardiac arrest survivors undergoing therapeutic hypothermia is associated with a good neurologic outcome.

BACKGROUND: The incidence of shivering in cardiac arrest survivors who undergo therapeutic hypothermia (TH) is varied. Its occurrence is dependent on the integrity of multiple peripheral and central neurologic pathways. We hypothesized that cardiac arrest survivors who develop shivering while undergoing TH are more likely to have intact central neurologic pathways and thus have better neurologic outcome as compared to those who do not develop shivering during TH. METHODS: Prospectively collected data on consecutive adult patients admitted to a tertiary center from 1/1/2007 to 11/1/2010 that survived a cardiac arrest and underwent TH were retrospectively analyzed. Patients who developed shivering during the cooling phase of TH formed the "shivering" group and those that did not formed the "non-shivering" group. The primary end-point: Pittsburgh Cerebral Performance Category (CPC) scale; good (CPC 1-2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. RESULTS: Of the 129 cardiac arrest survivors who underwent TH, 34/94 (36%) patients in the "non-shivering" group as compared to 21/35 (60%) patients in the "shivering" group had good neurologic outcome (P=0.02). After adjusting for confounders using binary logistic regression, occurrence of shivering (OR: 2.71, 95% CI 1.099-7.41, P=0.04), time to return of spontaneous circulation (OR: 0.96, 95% CI 0.93-0.98, P=0.004) and initial presenting rhythm (OR: 4.0, 95% CI 1.63-10.0, P=0.002) were independent predictors of neurologic outcome. CONCLUSION: The occurrence of shivering in cardiac arrest survivors who undergo TH is associated with an increased likelihood of good neurologic outcome as compared to its absence.

Risk of new-onset atrial fibrillation in elderly patients with the overlap syndrome: a retrospective cohort study.

OBJECTIVE: Co-existence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) is referred to as overlap syndrome. Overlap patients have greater degree of hypoxia and pulmonary hypertension than patients with OSA or COPD alone. Studies showed that elderly patients with OSA alone do not have increased risk of atrial fibrillation (AF) but it is not known if overlap patients have higher risk of AF. To determine whether elderly patients with overlap syndrome have an increased risk of AF. METHODS: In this single center, community-based retrospective cohort analysis, data were collected on 2,873 patients > 65 years of age without AF, presenting in the year 2006. Patients were divided into OSA group (n = 60), COPD group (n = 416), overlap syndrome group (n = 28) and group with no OSA or COPD (n = 2369). The primary endpoint was incidence of new-onset AF over the following two years. Logistic regression was performed to adjust for heart failure (HF), coronary artery disease, hypertension (HTN), cerebrovascular disease, cardiac valve disorders, diabetes mellitus, hyperlipidemia, chronic kidney disease (CKD) and obesity. RESULTS: The incidence of AF was 10% in COPD group, 6% in OSA group and 21% in overlap syndrome group (P < 0.05). After adjusting for age, sex, HF, CKD, and HTN, patients with overlap syndrome demonstrated a significant association with new-onset AF (OR = 3.66, P = 0.007). HF, CKD and HTN were also significantly associated with new-onset AF (P < 0.05). CONCLUSION: Among elderly patients, the presence of overlap syndrome is associated with a marked increase in risk of new-onset AF as compared to the presence of OSA or COPD alone.

The impact of severe acidemia on neurologic outcome of cardiac arrest survivors undergoing therapeutic hypothermia.

INTRODUCTION: Therapeutic Hypothermia (TH) has become a standard of care in improving neurological outcomes in cardiac arrest (CA) survivors. Previous studies have defined severe acidemia as plasma pH<7.20. We investigated the influence of severe acidemia at the time of initiation of TH on neurological outcome in CA survivors. METHODS: A retrospective analysis was performed on 196 consecutive CA survivors (out-of-hospital CA and in-hospital CA) who underwent TH with endovascular cooling between January 2007 and October 2012. Arterial blood gas drawn prior to initiation of TH was utilized to measure pH in all patients. Shockable and non-shockable CA patients were divided into two sub-groups based on pH (pH<7.2 and pH≥7.2). The primary end-point was measured using the Pittsburgh Cerebral Performance Category (CPC) scale prior to discharge from the hospital: good (CPC 1 and 2) and poor (CPC 3 to 5) neurologic outcome. RESULTS: Sixty-two percent of shockable CA patients with pH≥7.20 had good neurological outcome as compared to 34% patients with pH<7.20. Shockable CA patients with pH≥7.20 were 3.3 times more likely to have better neurological outcome when compared to those with pH <7.20 [p=0.013, OR 3.3, 95% CI (1.28-8.45)]. In comparison, non-shockable CA patients with p≥7.20 did not have a significantly different neurological outcome as compared to those with pH<7.20 [p=0.97, OR 1.02, 95% CI (0.31-3.3)]. CONCLUSION: Presence of severe acidemia at initiation of TH in shockable CA survivors is significantly associated with poor neurological outcomes. This effect was not observed in the non-shockable CA survivors.

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms.

BACKGROUND: Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms. METHODS: Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital. RESULTS: Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P=0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P=0.04) and 5.65 (CI 1.66-19.23, P=0.006) respectively. CONCLUSION: Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.

The use of hypothermia therapy in cardiac arrest survivors.

The annual incidence of out-of-hospital cardiac arrests in the United States is ∼350,000-450,000 per year. The prognosis for cardiac arrest survivors remains extremely poor. Therapeutic hypothermia (TH) is the only therapy proven to improve survival and neurological outcome in these patients. This article discusses the pathophysiology of neurological injury in cardiac arrest survivors and states the presumed mechanisms by which TH mitigates brain injury in these patients. It reviews the contraindications to the use of this therapy, methods of cooling, and phases of TH and elaborates on the intensive care unit management of TH. The use of TH in ventricular fibrillation survivors has become the standard of care and continues to evolve in its application as an essential therapy in cardiac arrest patients.