Negareh Mousavi

The impact of telemetry on survival of in-hospital cardiac arrests in non-critical care patients

OBJECTIVE Since the introduction of telemetry over a half century ago, it has expanded to various units and wards within health care institutions outside of the traditional critical care setting. Little is known on whether routine telemetry use is beneficial in this patient population. The aim of this study was to determine the impact of telemetry monitoring on survival of in-hospital cardiac arrests in patients admitted to non-critical care units. METHODS A retrospective study of cardiac arrests in patients admitted to non-critical care units within the Winnipeg Regional Health Authority from 2002 to 2006 inclusive was performed. Baseline demographic, cardiac arrest, and outcome data were collected. RESULTS Of the total 668 patients, the mean age was 70±14 years with 404 (61%) males. Patients presenting with asystole or pulseless electrical activity (PEA) demonstrated an increased mortality as compared to those presenting with ventricular tachycardia (VT) or ventricular fibrillation (VF). Overall, 268 of 668 patients (40%) survived their initial arrest, 66 (10%) survived to hospital discharge and 49 (7%) survived transfer to another facility. Patients on telemetry vs. no telemetry had higher survival rates immediately following cardiac arrest (66% vs. 34%, OR=3.67, p=0.02), as well as higher survival to hospital discharge (30% vs. 6%, OR=7.17, p=0.01). Finally, patients with cardiac arrest during the night and early morning benefited proportionally the greatest from telemetry use. CONCLUSION Regardless of whether cardiac arrest was witnessed or unwitnessed, telemetry use was an independent and strong predictor of survival to hospital discharge.

The utility of tissue Doppler imaging for the noninvasive determination of left ventricular filling pressures in patients with septic shock.

Background: Pulmonary artery wedge pressure (PAWP) is an important indicator of volume status in septic patients. Although it requires invasive pulmonary artery catheterization (PAC), a noninvasive method to assess PAWP would be clinically useful in this select patient population. Diastolic indices using transthoracic echocardiography (TTE) may provide an accurate estimate of PAWP. Objective: To determine whether echocardiographic Doppler assessment is accurate in estimating PAWP in patients with septic shock. Methods: A retrospective chart review was performed of 320 patients admitted with a diagnosis of septic shock from 2007-2008. Of the total patient population, 40 patients fulfilled the inclusion criteria, having undergone both TTE and PAC within 4 hours. Spectral Doppler indices including peak early (E) and late (A) transmitral velocities, E/A ratio, and E-wave deceleration time were measured. Tissue Doppler indices including S’, E’ and A’ velocities were determined. Pulmonary artery wedge pressure values measured invasively were compared to the dimensionless index of E/E’ in each patient. Results: The mean age was 68 ± 12 years with 28 males (70%). On echo assessment, 28% of patients had evidence of mild left ventricular diastolic dysfunction while 17% of patients had moderate diastolic dysfunction. Pulmonary artery wedge pressures ranged from 7 to 31 mm Hg with a mean of 18 ± 5 mm Hg. The mean E/E’ was 11 ± 8. Linear regression analysis between PAWP and E/E7apos; demonstrated a strong correlation (r = .84, P < .05). Conclusion: Tissue Doppler indices using TTE is a feasible and strong predictor of PAWP in patients with septic shock.

The Role of Three-Dimensional Echocardiography in the Assessment of Right Ventricular Dysfunction after a Half Marathon: Comparison with Cardiac Magnetic Resonance Imaging

BACKGROUND Although marathon running is associated with transient right ventricular (RV) systolic dysfunction as detected by two-dimensional transthoracic echocardiography, quantitative assessment of the right ventricle is difficult because of its complex geometry. Little is known about the use of real-time three-dimensional echocardiography (RT3DE) in the detection of cardiac dysfunction after a half marathon. The aim of this study was to assess the extent of RV dysfunction after the completion of a half marathon using cardiac biomarkers, RT3DE, and cardiac magnetic resonance imaging (CMR). METHODS A prospective study was performed in 15 individuals in 2009 participating in the Manitoba Half Marathon. Cardiac biomarkers (myoglobin, creatine kinase-MB and cardiac troponin T) were assessed and RT3DE and CMR were performed 1 week before, immediately after, and 1 week after the race. RESULTS At baseline, cardiac biomarkers and ventricular function were within normal limits. Immediately following the half marathon, all patients demonstrated elevated cardiac troponin T levels, with a median value of 0.37 ng/mL. RV ejection fraction, as assessed by RT3DE, decreased from 59 ± 4% at baseline to 45 ± 5% immediately following the race (P < .05). On CMR, RV end-diastolic volume increased after the half marathon, and the RV ejection fraction was reduced, at 47 ± 5% compared with 60 ± 2% at baseline (P < .05). There were strong linear correlations between RV ejection fraction assessed by RT3DE and CMR at baseline and after the half marathon (r = 0.69 and r = 0.87, P < .01, respectively). CONCLUSIONS Compared with CMR, RT3DE is a feasible and reproducible method of assessing transient RV dysfunction in athletes completing a half marathon.

Chiari Network Endocarditis: Not Just an Innocent Bystander

A Chiaris network, noted in approximately 2% of the general population, is a congenital remnant of the sinus venosum valve present in the right atrium. We report a case of a 67‐year‐old male who presented with acute infective endocarditis of the tricuspid valve due to coagulase‐negative Staphylococci. Despite appropriate antimicrobial therapy for 2 weeks, the patient remained febrile with septic emboli to the pulmonary vasculature. Repeat transthoracic echocardiography (TTE) revealed persistent vegetations adherent to the tricuspid valve, extending onto the Chiari network, necessitating surgical intervention.

Left ventricular pseudoaneurysm: The role of multimodality cardiac imaging

A 71-year-old man presented with an inferior ST elevation myocardial infarction. Coronary angiography demonstrated 99% occlusion of the proximal right coronary artery. A posterior wall pseudoaneurysm was incidentally observed on left ventriculography (arrows; Figure 1A). Transthoracic echocardiography revealed a site of rupture in the posterior left ventricular (LV) wall measuring 36 mm in width, communicating with a large, thrombus-free pseudoaneurysm (asterisks; Figure 1B). Cardiac magnetic resonance imaging (MRI) confirmed the presence of an aneurysmal dilation along the basal inferolateral wall with a mouth orifice of 36 mm in diameter and 36 mm deep (arrows; Figure 1C). A rim of delayed enhancement around the aneurysm could have represented either a full-thickness myocardial scar or an enhancing pericardium containing a false aneurysm, although the location was of concern for the latter (arrows; Figure 1D). At surgery, following resection of the aneurysmal sac (Figure 1E), an examination of the interior of the LV wall revealed a zone of transition from healthy-appearing myocardium to thinned scarred myocardium, followed by a thinner fibrous edge, which was compatible with the diagnosis of a pseudoaneurysm. Pathological examination demonstrated organizing fibrous tissue (Figure 1F). The lack of LV wall was consistent with the diagnosis of a pseudoaneurysm. Figure 1) Ao Aorta; LA Left atrium; LV Left ventricle; RV Right ventricle LV pseudoaneurysms develop when myocardial rupture is contained by pericardial adhesions or scar tissue (1). In contrast, true LV aneurysms form following myocardial infarction as a result of scar formation and thinning of the myocardial wall. Echocardiography, left ventriculography and cardiac MRI are complementary imaging modalities used to distinguish theses two entities. Cardiac MRI, with its higher spatial resolution, is more sensitive and specific for the diagnosis of a pseudoaneurysm than transthoracic echocardiography (2). The absence of delayed enhancement findings of myocardial elements within the sac of the aneurysm on cardiac MRI, and the presence of delayed enhancement of the pericardium, is highly suggestive of a pseudoaneurysm (2). In some cases, however, such as in the present patient, differentiation of a delayed enhancement of the myocardium from an adjacent pericardium may be challenging, leading to an incorrect diagnosis because an enhancing pericardium containing a pseudoaneurysm can mimic an infarcted myocardium (2). Hence, surgical assessment and pathological evaluation is occasionally imperative to make a definitive diagnosis.

Case of the Month #166: Carcinoid Heart Disease

A previously healthy 60-year-old woman presented with a 3-week history of fatigue and exertional dyspnea. Over the past year, she had experienced episodic wheezing, facial flushing, diarrhoea, and an unintentional 40-lb weight loss. On physical examination, she demonstrated venous telangiectasia in the malar region, mild peripheral cyanosis, and an elevated jugular venous pressure with a dominant V wave. On cardiac auscultation, there was a holosystolic murmur at the left lower sternal region of grade III/VI intensity that increased on inspiration. Transthoracic echocardiography was performed to confirm the valvular abnormalities detected on physical examination (Figure 1A). Cardiac magnetic resonance imaging (CMR) was performed to quantify right ventricular systolic function and computed tomography of the abdomen was performed as shown Figures 1B and C.

Interventricular septal cleft aneurysm.

A 57-year-old man with a history significant for a bicuspid aortic valve and repaired coarctation of the aorta at 10 years of age, underwent transthoracic echocardiography for routine follow-up. Transthoracic echocardiography revealed a bicuspid aortic valve with a moderate degree of aortic regurgitation. A cleft aneurysm (arrow) was incidentally noted in the midinterventricular septal region on the left ventricular (LV) side, measuring 11 mm × 5 mm (Figure 1A and Video 1A). There was no flow across the defect on colour Doppler imaging to suggest a ventricular septal defect. Cardiac magnetic resonance imaging confirmed the presence of a focal cleft (arrow) within the midventricular septum on the LV side, extending over a length of 8 mm and to a depth of 7 mm (Figure 1B and Video 1B). Figure 1 LA Left atrium; LV Left ventricle; RA Right atrium; RV Right ventricle Aneurysms of the muscular interventricular septum are a distinct entity with a poorly defined etiology and clinical course. Acquired causes secondary to coronary artery disease, coronary anomalies, trauma, infections, cardiac surgery and Kawasaki disease have been described. In the absence of a readily identifiable acquired etiology, idiopathic septal cleft aneurysms are believed to be congenital. There was no evidence of delayed enhancement of the LV myocardium on cardiac magnetic resonance imaging to suggest an ischemic etiology of the cleft aneurysm. Potential cardiac complications include rupture, cardiac arrhythmias, congestive heart failure and thromboembolism. Although management is generally conservative, as in the present patient, surgical excision with repair is recommended in high-risk or symptomatic patients.