Kanwal Kumar

The impact of repeated marathon running on cardiovascular function in the aging population

BackgroundSeveral studies have correlated elevations in cardiac biomarkers of injury post marathon with transient and reversible right ventricular (RV) systolic dysfunction as assessed by both transthoracic echocardiography (TTE) and cardiovascular magnetic resonance (CMR). Whether or not permanent myocardial injury occurs due to repeated marathon running in the aging population remains controversial.ObjectivesTo assess the extent and severity of cardiac dysfunction after the completion of full marathon running in individuals greater than 50 years of age using cardiac biomarkers, TTE, cardiac computed tomography (CCT), and CMR.MethodsA total of 25 healthy volunteers (21 males, 55 ± 4 years old) from the 2010 and 2011 Manitoba Full Marathons (26.2 miles) were included in the study. Cardiac biomarkers and TTE were performed one week prior to the marathon, immediately after completing the race and at one-week follow-up. CMR was performed at baseline and within 24 hours of completion of the marathon, followed by CCT within 3 months of the marathon.ResultsAll participants demonstrated an elevated cTnT post marathon. Right atrial and ventricular volumes increased, while RV systolic function decreased significantly immediately post marathon, returning to baseline values one week later. Of the entire study population, only two individuals demonstrated late gadolinium enhancement of the subendocardium in the anterior wall of the left ventricle, with evidence of stenosis of the left anterior descending artery on CCT.ConclusionsMarathon running in individuals over the age of 50 is associated with a transient, yet reversible increase in cardiac biomarkers and RV systolic dysfunction. The presence of myocardial fibrosis in older marathon athletes is infrequent, but when present, may be due to underlying occult coronary artery disease.

Minimally invasive left-heart decompression during venoarterial extracorporeal membrane oxygenation: an alternative to a percutaneous approach.

Decompression of the left-heart following initiation of extracorporeal membrane oxygenation, is at times required. In the setting of a closed chest this can present a challenge. We present a minimally invasive approach to left-heart decompression in an adult-sized patient, where a percutaneous option was not feasible.

Hearts From DCD Donors Display Acceptable Biventricular Function After Heart Transplantation in Pigs

Cardiac transplantation is in decline, in contrast to other solid organs where the number of solid organ transplants from donors after circulatory death (DCD) is increasing. Hearts from DCD donors are not currently utilized due to concerns that they may suffer irreversible cardiac injury with resultant poor graft function. Using a large animal model, we tested the hypothesis that hearts from DCD donors would be suitable for transplantation. Donor pigs were subjected to hypoxic cardiac arrest (DCD) followed by 15 min of warm ischemia and resuscitation on cardiopulmonary bypass, or brainstem death (BSD) via intracerebral balloon inflation. Cardiac function was assessed through load‐independent measures and magnetic resonance imaging and spectroscopy. After resuscitation, DCD hearts had near normal contractility, although stroke volume was reduced, comparable to BSD hearts. DCD hearts had a significant decline in phosphocreatine and increase in inorganic phosphate during the hypoxic period, with a return to baseline levels after reperfusion. After transplantation, cardiac function was comparable between BSD and DCD groups. Therefore, in a large animal model, the DCD heart maintains viability and recovers function similar to that of the BSD heart and may be suitable for clinical transplantation. Further study is warranted on optimal reperfusion strategies.

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.

Infective Endocarditis in the Intensive Care Unit

Infective endocarditis has many facets and various expressions depending on the site of infection, microorganism, underlying heart lesion, immune status of the host, and remote effects such as emboli, organ dysfunction, and the condition of the host. Diagnosis depends on meticulous clinical examination, blood cultures results, and echocardiographic findings. The management of the patient with endocarditis in the intensive care unit is complex and needs a multidisciplinary team, including an intensivist, cardiologist, experienced echocardiologist, infectious diseases specialist, and cardiac surgeon. The medical and surgical management of such patients is complex, and timely decisions are important.

Meningococcal serotype Y myopericarditis

Involvement of the pericardium in meningococcal disease is a well-recognized but rare complication. Isolated meningococcal pericarditis is defined as purulent pericarditis without clinical evidence of meningococcemia. Neisseria meningitidis serotypes C, B, and W135 have been previously described to cause pericarditis. This is the 1st case report of isolated meningococcal myopericarditis due to N. meningitidis serotype Y.

The Role of Tissue Doppler Imaging in Predicting Left Ventricular Filling Pressures in Patients Undergoing Cardiac Surgery: An Intraoperative Study

Introduction: The perioperative management of patients undergoing cardiac surgery usually requires the accurate assessment of left ventricular filling pressures (LVFP). The gold standard for determining LVFP involves the use of pulmonary artery catheters (PAC). Using tissue Doppler indices (TDI) obtained by transthoracic echocardiography, the ratio of early transmitral filling velocity to the corresponding early mitral annular velocity (E/E′) has a strong correlation with pulmonary capillary wedge pressure (PCWP). Little is known, however, on whether this relationship between E/E′ and PCWP is valid intraoperatively using transesophageal echocardiography (TEE) during cardiac surgery. Objective: The objective of our study was to determine whether TDI obtained by intraoperative TEE during cardiac surgery can accurately estimate PCWP using PAC as the gold standard. Methods and Results: A total of 34 patients (26 males, mean age 64 ± 9 years) undergoing cardiac surgery were prospectively enrolled between 2010 and 2011 at a single tertiary care center. Conventional diastolic and tissue Doppler parameters were evaluated using intraoperative TEE with concurrent PAC monitoring before and after cardiopulmonary bypass (CPB) surgery. At both pre‐ and post‐CPB, there was no significant correlation between lateral, septal, and mean E/E′ obtained by TEE and PCWP. Conclusion: Intraoperative TEE was unable to accurately predict LVFP in patients undergoing cardiac surgery. PAC may continue to be the gold standard in the assessment of LVFP for this patient population.

Simultaneous Salmonella spp. endocarditis and mycotic abdominal aortic aneurysm presentation: a surgical dilemma

Concomitant valvular and abdominal aortic pathologies, both requiring urgent surgical interventions, are an uncommon entity. The ideal surgical management of such a scenario varies, depending on a host of variables. Due to its complexity and rarity, the ideal management approach remains an unknown. We describe a patient who presents with a delayed diagnosis of concomitant Salmonella species mitral valve (MV) endocarditis and mycotic abdominal aortic aneurysm (AAA). Though both clinical entities required urgent surgical intervention, the presence of one made intervening for the other high-risk and created a surgical dilemma. Following guarded conservative medical management, the patient underwent successful staged surgical interventions.

Current myocardial infarction classification does not predict risks of early revascularization.

BACKGROUND Compared with non-ST-elevation myocardial infarction (MI), ST-elevation MI has been associated with increased mortality after medical treatment and percutaneous coronary intervention. Our study investigated the prognostic value of MI classification in the setting of surgical revascularization within 21 days of MI. METHODS We studied 2412 consecutive patients between 1995 and 2007 who underwent an isolated coronary artery bypass grafting procedure within 21 days after MI. The outcomes of interest were in-hospital mortality and major adverse events, which included death, MI, stroke, and renal failure requiring hemodialysis. RESULTS Rates of crude in-hospital mortality and major adverse events were higher in ST-elevation MI patients. Stepwise regression analysis suggested that MI subtype (ST-elevation MI vs non-ST-elevation MI) did not predict in-hospital mortality or major adverse events. A secondary analysis using propensity score matching showed similar surgical outcomes between the two cohorts. CONCLUSIONS Surgical risks of patients with recent MI are independent of MI subtype. Distinguishing ST-elevation MI and non-ST-elevation MI is of limited value in the decision-making process of early surgical intervention.