Novel co-enrichment method for isolation of magnetotactic bacteria.

A novel co-enrichment technique was designed for enrichment of magnetotactic bacteria from soil, water, and sediments. Delayed addition of iron uptake inducer and the iron source proved amenable to induce magnetosome synthesis by MTB followed by their separation from consortium using magnetic flux. We successfully enriched and isolated both North seeking as well as South seeking magnetotactic bacteria from Lonar Lake (Buldhana), Moti Lake (Jalna), Ghanewadi Lake (Jalna), Ganesh Lake (Miraj), Rankala Lake (Kolhapur), and industrial metal-contaminated glaying soils (Jalna) and a soil (Karad), (MS, India) exposed to high-voltage electric current. The hanging drop preparations and growth under magnetic stress on low-agar media allowed conformation of magnetotactic behavior of the isolates. Both Gram positive and Gram negative MTB were isolated with diverse morphologies. South seeking population was more predominant. The soil inhabitants showed little dwelling property which was more prominent in case of aquatic inhabitants. The use of in situ pH and salt concentrations during enrichment and isolation found suited. The simultaneous growth of whole consortium in the system ensured the in situ simulation of microenvironment needful for proper growth of fastidious MTB.

Permanent Pacemaker-Mediated Exertional Hypoxemia in a Patient With Ebstein Anomaly.

Patients with Ebstein anomaly are known to have a higher incidence of interatrial communications and shunting of blood and its components through, mainly due to either streaming of tricuspid regurgitation or due to elevated right atrial pressure. Here we describe a case where permanent pacemaker lead kept a patent foramen ovale open leading to right-to-left shunting of blood and exertional hypoxemia. This is the first such case report in the published literature.

Cardiovascular magnetic resonance in mild to moderate clozapine-induced myocarditis: is there a role in the absence of electrocardiographic and echocardiographic abnormalities?

Clozapine is an atypical, neuroleptic medication that can cause myocarditis. While the "gold standard" for diagnosis of myocarditis is perceived to be via myocardial biopsy, cardiovascular magnetic resonance (CMR) has also proven its utility in this respect, primarily through its ability to detect myocardial scar by late-gadolinium enhancement (LGE). Until recently, however, clozapine-induced myocarditis specifically has not been known to be associated with LGE on CMR. In that particular case, LGE was demonstrated in a patient with clozapine-induced myocarditis. However, quite important, that patient also had specific abnormalities on the electrocardiogram (ECG) and echocardiogram that corresponded to the area of LGE demonstrated by CMR. We highlight a case series of three patients with clozapine-induced myocarditis and provide a literature review to discuss and critically appraise the true incremental diagnostic value of CMR in such patients with normal ECG and echocardiography.

An unusual case of left ventricular aneurysm in duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) leads to structural heart disease, including dilated cardiomyopathy, in 90% of patients >18 years of age. Despite the ubiquity of cardiomyopathy associated with DMD, ventricular aneurysms in these patients have rarely been reported. We present a case of a basal inferoposterior aneurysm of the left ventricle in a 23-year-old male patient with DMD.

Patent Foramen Ovale Treatment Strategies Correspond to an Index Predicting Pathogenicity.

BACKGROUND: Percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke (CS) may reduce the risk of recurrent stroke. By performing closure only in those with high risk of recurrent PFO related strokes, patient selection may be improved. The Risk of Paradoxical Embolism (RoPE) score is a point-based index developed to estimate the probability that the index CS was attributable to patent foramen ovale. We aimed to evaluate whether management strategies using conventional clinical judgement for patients with CS and PFO corresponded with RoPE scores. METHODS: We performed a single-centre retrospective chart review of adult patients with CS or transient ischemic attack who were evaluated for PFO closure from January 1, 2011 to December 31, 2017. Patients were categorized based on the treatment strategy of percutaneous closure or medical management. RoPE scores were computed and clinical outcomes evaluated. RESULTS: A total of 154 patients were included: 63 patients underwent percutaneous closure and 91 patients were treated medically. Mean RoPE scores for closure and medical groups were 6.9±1.5 and 4.7±1.9, respectively (p<0.001). For patients who underwent percutaneous closure, successful device delivery was achieved in all patients and there were no immediate complications. CONCLUSION: In this single-centre study, patients selected for percutaneous PFO closure based on conventional clinical judgement were more likely to have elevated PFO attributable risk, based on the RoPE score.

Exercise-induced improvement in atrial depolarization abnormality in a patient after treatment with beta-adrenergic blockers.

Abnormal atrial depolarization, characterized by P waves >or=110 ms on the electrocardiogram, can manifest as partial or advanced interatrial conduction delay or interatrial block (IAB). Progression from partial to advanced IAB has been shown to be altered by the use of angiotensin-converting enzyme inhibitors and beta-adrenergic blockers. We previously reported that advanced IAB, denoted by biphasic P waves in leads II, II and aVF, can revert intermittently to its partial counterpart. However, potential factors that could induce such resolution remain unknown. We present the first known case of resolution of advanced IAB to partial IAB occurring during graded exercise, following treatment with a beta-adrenergic blocker. Only continued study of these and other novel factors will help us understand the exact pathophysiology of both, partial and advanced IAB.

Diagnostic value of harmonic transthoracic echocardiography in native valve infective endocarditis: comparison with transesophageal echocardiography.

BACKGROUND: Although echocardiography has been incorporated into the diagnostic algorithm of patients with suspected infective endocarditis (IE), systematic usage in clinical practice remains ill defined. To determine the diagnostic accuracy of detecting vegetations using harmonic transthoracic echocardiography (hTTE) as compared to transesophageal echocardiography (TEE) in patients with an intermediate likelihood of native valve IE. METHODS: Between 2004 and 2005, 36 consecutive inpatients with an intermediate likelihood of disease were prospectively evaluated by hTTE and TEE. RESULTS: Of 36 patients (21 males with a mean age of 57 +/- 15 years, range 32 to 86 years), 19 patients had definite IE by TEE. The sensitivity for the detection of vegetations by hTTE was 84%, specificity of 88%, positive predictive value (PPV) of 89% and negative predictive value (NPV) of 82%. The association between hTTE and TTE interpretation for the presence and absence of vegetations were high (kappa = 0.90 and 0.85 respectively). CONCLUSION: In patients with an intermediate likelihood of native valve IE, TTE with harmonic imaging provides diagnostic quality images in the majority of cases, has excellent concordance with TEE and should be recommended as the first line test.

Multimodality cardiac imaging of a left ventricular papillary fibroelastoma: a case report.

BACKGROUND: In the setting of an acute myocardial infarction (AMI), although the most common etiology of a left ventricular (LV) mass identified on multimodality cardiovascular imaging is a thrombus, other possibilities including a vegetation or tumor should be entertained within the differential diagnosis. CASE PRESENTATION: We describe a case of a 43-year-old Caucasian female post AMI diagnosed with a mid-cavitary mass within the LV. Although echocardiography and cardiovascular MRI (CMR) suggested that the mass was a thrombus, given the context of the recent AMI, exploration and surgical excision was completed by the surgeon due to the potential for the mass to embolize. CONCLUSION: The final diagnosis of a papillary fibroelastoma was unique due to its unusual location and large size within the LV cavity. This unique case demonstrates shortcomings of multimodality cardiac imaging in the diagnosis of an atypical mass and the importance of obtaining tissue when clinically safe and feasible.

Analysis of Short- and Long-term Outcomes of Patients With Surgically Treated Left-sided Infective Endocarditis: A 5-Year Longitudinal Follow-up Study.

This study aims to analyze survival, repeat hospitalization, and risk factors for surgically treated left-sided endocarditis. Retrospective review of all 166 (114 native and 52 prosthetic) patients operated between January 2004 and March 2015 was performed. Long-term survival and repeat hospitalization data for 134 of 166 patients were obtained via linked clinical databases with the Manitoba Centre for Health Policy. Kaplan-Meier estimates of survival and hospital readmission and Cox multivariable regression analysis of factors influencing outcomes were performed. Survival at 1 and 5 years was 91% and 80%, respectively, and major adverse prosthesis-related event repeat hospitalization rates were 12% and 21%, respectively. Repeat hospitalization because of endocarditis was 7% and 11% at 1 and 5 years, respectively. Survival and repeat hospitalization were similar for aortic and mitral valves. Survival after surgically treated endocarditis was similar to survival for age-, sex-, and valve-matched surgical valve replacements for noninfectious indications (P = 0.53). Viridans Streptococci was the most common organism in native valve endocarditis, and culture negative endocarditis was most common in prosthetic valves. Prosthetic valve endocarditis (P < 0.01) and preoperative renal dysfunction (P < 0.01) were risk factors for in-hospital mortality and major postoperative adverse events. Diabetes and renal dysfunction were associated with poor long-term survival, functional survival, and repeat hospitalization. This analysis suggests that surgery remains a very effective tool in management of these complex patients in terms of survival and major adverse prosthesis-related event repeat hospitalization.

Venous Diversion Surgery Revisited: A Baffling Situation.

With the increasing number of survivors with congenital heart disease (CHD) reaching adulthood, it is important for the clinician to be familiar with the various surgical options performed in this growing patient population. We describe the case of a 65-year-old female who presented with hypoxia and right-to-left shunting following a surgical repair of an atrial septal defect (ASD) secundum and anomalous pulmonary veins with a partial atrial diversion procedure in childhood. The use of multimodality cardiovascular imaging using echocardiography, computed tomography, magnetic resonance imaging, and invasive cardiac catheterization was complementary in the preoperative diagnosis and management of this unique baffling situation.

Cardiac perforation after device closure of atrial septal defects with the Amplatzer septal occluder.

OBJECTIVES: Amplatzer septal occluder (ASO)-associated cardiac perforation (CP) at our institution prompted this retrospective review. BACKGROUND: Cardiac perforation is a rare complication after transcatheter atrial septal defect (ASD) closure. METHODS: To identify CP after transcatheter ASD closure with ASO, cardiac events (CE) describing definite CP, hemopericardium, pericardial effusion, cardiovascular collapse, or sudden death were analyzed. Cardiac events were identified from published literature (MEDLINE), medical device regulating agencies in North America and the European Commission, and AGA Medical Corporation (Golden Valley, Minnesota). Institutional cases were reviewed. Cardiac events were defined as early (pre-discharge) or late (post-discharge). RESULTS: Twenty-nine CEs were identified. Five were excluded because findings were inconclusive for device-related CP. Ten patients were <18 years of age. Late CEs occurred in 66.6%; 25% presented weeks later (longest, three years). Three deaths were reported. Cardiac perforation occurred predominantly in the anterosuperior atrial walls and/or adjacent aorta. CONCLUSIONS: Amplatzer septal occluder-associated CP uniquely involves the anterosuperior atrial walls and adjacent aorta. Pathophysiology remains poorly understood.

Abiotrophia endocarditis: case report and review of the literature.

Abiotrophia is a separate genus of gram-positive cocci formerly classified as nutritionally variant streptococci. These organisms cause 1% to 2% of all infective endocarditis. Unlike Enterococcus or viridans group streptococci, these organisms do not usually grow on conventional blood agar plates. Therefore, Abiotrophia endocarditis is often falsely lumped into the category of culture-negative endocarditis. Adequate diagnosis and treatment of this entity requires a high index of suspicion for the organisms, even if cultures are negative. Nutritional supplementation of the growth media and/or newer 16S ribosomal RNA gene sequencing may be necessary to identify Abiotrophia as the causative organism. Specific antimicrobial therapy and continued surveillance are needed to prevent the significant morbidity and mortality associated with this infection.

Multimodality cardiac imaging of a left ventricular thrombus: a case report.

BACKGROUND: Left ventricular thrombus (LVT) formation occasionally complicates patient recovery post myocardial infarction, conveying a significant risk of systemic embolism. Accordingly, thrombus detection and subsequent anticoagulation is imperative in order to minimize patient morbidity and mortality. Transthoracic echocardiography (TTE) is the imaging modality most widely used to screen for thrombus formation despite its suboptimal sensitivity and specificity. CASE PRESENTATION: This report describes the discordant imaging findings of a LVT in a 56 year old Caucasian male with an anterior ST elevation myocardial infarction. Left ventriculography revealed a filling defect, suggestive of a potential left ventricular (LV) thrombus, which could not be confirmed by TTE. Cardiac magnetic resonance imaging (MRI) demonstrated evidence of a full thickness scar involving the mid to distal anterior wall and apical regions, with confirmation of a small LV apical thrombus. CONCLUSIONS: This case illustrates the limitations of TTE when used as a tool to screen for thrombus formation. It highlights the importance of multimodality cardiac imaging for the detection of post myocardial infarction (MI) complications, in the context of a high clinical suspicion.

The presence of ST-elevation in lead aVR predicts significant left main coronary artery stenosis in cardiogenic shock resulting from myocardial infarction: the Manitoba cardiogenic shock registry.

INTRODUCTION: Electrocardiographic (ECG) predictors of significant angiographic left main coronary artery stenosis (LMCS>50%) have been described in acute myocardial infarction using ST-segment elevation in lead aVR (aVR-STE). However, there is a paucity of data on its association with LMCS>50% in the setting of cardiogemic shock (CGS). METHODS: We investigated 210 consecutive, unselected, patients from Sept. 2002-2006 with CGS due to acute myocardial infarction undergoing cardiac catheterization. Of those, 191 patients with interpretable ECG tracings for aVR-STE analysis formed our study sample. aVR-STE was defined as ST-segment elevation≥1mm in aVR while LMCS>50% on coronary angiogram was defined as any left main lesion that demonstrated >50% lumen narrowing or equivalent by direct visualization or quantitative coronary angiography analysis. RESULTS: There was 59% survival to discharge of this predominantly male cohort (median age 68±12years; 31% females). Fifty three (28%) cases had aVR-STE while 27 (14%) had LMCS>50%. Of those, 16 patients who had aVR-STE also had LMCS>50% (sensitivity 59%, specificity 77%, positive predictive value 30%, negative predictive value 92% for predicting LMCS>50%). Multivariate analysis revealed that aVR-STE was the only significant predictor of LMCS>50% was (p=0.014; Odds Ratio=3.06; 95% Confidence Interval 1.26-7.47). CONCLUSION: In CGS due to acute myocardial infarction, aVR-STE>1mm proves to be an important predictor of LMCS>50%. Such data could be helpful in further risk stratification for optimal management during CGS.

Electrocardiographic criteria in tako-tsubo cardiomyopathy-is there added certainty in a diagnosis per exclusionem?

Tako-Tsubo cardiomypathy (TTC), also known as transient left ventricular apical ballooning syndrome, is a stress-induced cardiomyopathy that predominantly affects post-menopausal, elderly women during emotional or physical stress. Apical left ventricular dysfunction in the absence of significant coronary artery disease is the hallmark of this condition. Because the electrocardiogram (ECG) classically depicts precordial ST-segment elevations and cardiac biomarkers can often be raised, it can be a challenge to differentiate TTC from an acute myocardial infarction (AMI). Indeed, several recent studies have proposed ECG criteria to differentiate TTC from an AMI. We present a case series of consecutive patients in whom we had employed such ECG criteria but were unable to conclusively differentiate TTC from an AMI. In each case, TTC remained a diagnosis per exclusionem, where coronary angiography was necessary to rule out myocardial infarction. We review and discuss the commonly used ECG criteria and highlight the evolutionary ECG changes commonly noted with TTC to help better prepare clinicians when dealing with patients with similar clinical scenarios.