Obstruction of the inferior vena cava following bicaval orthotopic heart transplantation: a case series.

BACKGROUND: Inferior vena cava (IVC) obstruction is a rare complication of orthotopic heart transplantation (OHT) and is unique to bicaval surgical technique. The clinical significance, diagnosis, complications, and management of post-operative IVC anastomotic obstruction have not been adequately described. CASE SUMMARY: Two patients with end-stage heart failure presented for bicaval OHT. Post-operative course was complicated with shock refractory to fluid resuscitation and inotropic/vasopressor support. Obstruction at the IVC-right atrial (RA) anastomosis was diagnosed on transoesophageal echocardiography (TOE), prompting emergent reoperation. In both cases, a large donor Eustachian valve was found to be restricting flow across the IVC-RA anastomosis. Resection of the valve resulted in relief of obstruction across the anastomosis and subsequent improvement in haemodynamics and clinical outcome. DISCUSSION: Presumably rare, we present two cases of IVC obstruction post-bicaval OHT. Inferior vena cava obstruction is an under-recognized cause of refractory hypotension and shock in the post-operative setting. Prompt recognition using TOE is crucial for immediate surgical correction and prevention of multi-organ failure. Obstruction can be caused by a thickened Eustachian valve caught in the suture line at the IVC anastomosis, which would require surgical resection.

Burden of arrhythmia in hospitalized HIV patients.

BACKGROUND: The improved life expectancy observed in patients living with human immunodeficiency virus (HIV) infection has made age-related cardiovascular complications, including arrhythmias, a growing health concern. HYPOTHESIS: We describe the temporal trends in frequency of various arrhythmias and assess impact of arrhythmias on hospitalized HIV patients using the Nationwide Inpatient Sample (NIS). METHODS: Data on HIV-related hospitalizations from 2005 to 2014 were obtained from the NIS database using International Classification of Diseases, 9th Revision (ICD-9) codes. Data was further subclassified into hospitalizations with associated arrhythmias and those without. Baseline demographics and comorbidities were determined. Outcomes including in-hospital mortality, cost of care, and length of stay were extracted. SAS 9.4 (SAS Institute Inc., Cary, NC) was utilized for analysis. A multivariable analysis was performed to identify predictors of arrhythmias among hospitalized HIV patients. RESULTS: Among 2 370 751 HIV-related hospitalizations identified, the overall frequency of any arrhythmia was 3.01%. Atrial fibrillation (AF) was the most frequent arrhythmia (2110 per 100 000). The overall frequency of arrhythmias increased over time by 108%, primarily due to a 132% increase in AF. Arrhythmias are more frequent among older males, lowest income quartile, and nonelective admissions. Patients with arrhythmias had a higher in-hospital mortality rate (9.6%). In-hospital mortality among patients with arrhythmias decreased over time by 43.8%. The cost of care and length of stay associated with arrhythmia-related hospitalizations were mostly unchanged. CONCLUSIONS: Arrhythmias are associated with significant morbidity and mortality in hospitalized HIV patients. AF is the most frequent arrhythmia in hospitalized HIV patients.

Feasibility of selective cardiac ventricular electroporation.

INTRODUCTION: The application of brief high voltage electrical pulses to tissue can lead to an irreversible or reversible electroporation effect in a cell-specific manner. In the management of ventricular arrhythmias, the ability to target different tissue types, specifically cardiac conduction tissue (His-Purkinje System) vs. cardiac myocardium would be advantageous. We hypothesize that pulsed electric fields (PEFs) can be applied safely to the beating heart through a catheter-based approach, and we tested whether the superficial Purkinje cells can be targeted with PEFs without injury to underlying myocardial tissue. METHODS: In an acute (n = 5) and chronic canine model (n = 6), detailed electroanatomical mapping of the left ventricle identified electrical signals from myocardial and overlying Purkinje tissue. Electroporation was effected via percutaneous catheter-based Intracardiac bipolar current delivery in the anesthetized animal. Repeat Intracardiac electrical mapping of the heart was performed at acute and chronic time points; followed by histological analysis to assess effects. RESULTS: PEF demonstrated an acute dose-dependent functional effect on Purkinje, with titration of pulse duration and/or voltage associated with successful acute Purkinje damage. Electrical conduction in the insulated bundle of His (n = 2) and anterior fascicle bundle (n = 2), was not affected. At 30 days repeat cardiac mapping demonstrated resilient, normal electrical conduction throughout the targeted area with no significant change in myocardial amplitude (pre 5.9 ± 1.8 mV, 30 days 5.4 ± 1.2 mV, p = 0.92). Histopathological analysis confirmed acute Purkinje fiber targeting, with chronic studies showing normal Purkinje fibers, with minimal subendocardial myocardial fibrosis. CONCLUSION: PEF provides a novel, safe method for non-thermal acute modulation of the Purkinje fibers without significant injury to the underlying myocardium. Future optimization of this energy delivery is required to optimize conditions so that selective electroporation can be utilized in humans the treatment of cardiac disease.

A novel percutaneous stabilizing sheath for minimal invasive epicardial echocardiography and ablation.

PURPOSE: Epicardial ablation and mapping are critical adjuncts to the electrophysiologist's approach to arrhythmias; however, ablation within the epicardial space requires the avoidance of coronary arteries (CA). We aimed to evaluate the feasibility and performance of a novel-stabilizing ablation sheath housing an intracardiac echocardiography (ICE) catheter to (1) obtain Epicardial Echocardiography (EE) images, (2) visualize CAs, and (3) enable targeted delivery of radiofrequency energy away from visualized CAs. METHODS: We designed a sheath that could enclose a regular ICE catheter. This sheath has flanges and a balloon, with three interspersed windows surrounded by an electrode. In an acute canine model (N = 6), the sheath was manipulated within the pericardial space to visualize cardiac structures and CAs. Visualization of CAs was confirmed with angiography. Ablation was then performed through the window either proximal or distal to the CA. RESULTS: The novel sheath was successfully deployed in six canines, with no acute procedural complications. Images with an excellent spatial resolution of cardiac structures were obtained including the right ventricular outflow tract; aortic, pulmonary, and mitral valves; and left atrial appendage. CAs were successfully visualized, and ablation from a sheath window either proximal or distal to the CA did not produce angiographic or histopathological evidence of CA damage despite evidence of acute injury to the adjacent ablated myocardium. CONCLUSIONS: This novel percutaneous stabilizing sheath was able to successfully obtain high-quality EE images as well as provide a non-fluoroscopic intra-procedural means to visualize CAs. Use of this sheath enabled successful delivery of energy to avoided CA damage.

Development of a novel ablation hood to prevent systemic embolization of microbubbles and particulate emboli.

BACKGROUND: Atrial fibrillation ablation results in microbubbles and particulate emboli formation. We aimed to develop and test the early feasibility of a novel ablation hood to contain microbubbles and particulate emboli with the ultimate goal of preventing systemic embolization. METHODS: In seven canines, we developed, iterated, and tested a novel retractable hood that can cover the catheter-tissue ablation site. The number and volume (nL) of microbubbles formed during ablation with and without the hood was measured using an extracorporeal circulation loop. Wilcoxon's signed-rank test was used to compare the number of bubbles detected with and without the hood. RESULTS: The hood reduced systemic embolization of microbubbles in 21/28 (75%) of ablations. Both atrial and ventricular ablations showed a statistically significant reduction in bubble number (476 ± 811 without hood vs 173 ± 226 with hood, p = 0.02; 2669 ± 1623 without hood vs 1417 ± 970 with hood, p = 0.04, respectively) and bubble volume (3.3 ± 7.6 nL without hood vs 0.2 ± 0.56 nL with hood, p = 0.006; 6.1 ± 5.2 nL without hood vs 1.9 ± 1.4 nL with hood, p = 0.05, respectively). CONCLUSIONS: Use of a novel hood to cover the ablation catheter at the site of catheter-tissue contact has the potential to provide a means to reduce systematic embolization of microbubbles. Further work is required to examine particulate emboli, but these data show the early feasibility of this design concept.

Safety and compatibility of smart device heart rhythm monitoring in patients with cardiovascular implantable electronic devices.

INTRODUCTION: Emerging medical technology has allowed for monitoring of heart rhythm abnormalities using smartphone compatible devices. The safety and utility of such devices have not been established in patients with cardiac implantable electronic devices (CIEDs). We sought to assess the safety and compatibility of the Food and Drug Administration-approved AliveCor Kardia device in patients with CIEDs. METHODS AND RESULTS: We prospectively recruited patients with CIED for a Kardia recording during their routine device interrogation. A recording was obtained in paced and nonpaced states. Adverse clinical events were noted at the time of recording. Electrograms (EGMs) from the cardiac device were obtained at the time of recording to assess for any electromagnetic interference (EMI) introduced by Kardia. Recordings were analyzed for quality and given a score of 3 (interpretable rhythm, no noise), 2 (interpretable rhythm, significant noise) or 1 (uninterpretable). A total of 251 patients were recruited (59% with a pacemaker and 41% with ICD). There were no adverse clinical events noted at the time of recording and no changes to CIED settings. Review of all EGMs revealed no EMI introduced by Kardia. Recordings were correctly interpreted in 90% of paced recordings (183 had a score of 3, 43 of 2, and 25 of 1) and 94.7% of nonpaced recordings (147 of 3, 15 of 2, and 9 of 1). CONCLUSION: The AliveCor Kardia device has an excellent safety profile when used in conjunction with most CIEDs. The quality of recordings was preserved in this population. The device, therefore, can be considered for heart rhythm monitoring in patients with CIEDs.

The efficacy and safety of electroanatomic mapping-guided endomyocardial biopsy: a systematic review.

PURPOSE: Electroanatomic mapping (EAM) has been utilized as a modality to improve the sensitivity of endomyocardial biopsy (EMB). We sought to systematically review published medical literature on the efficacy and safety of EAM-guided EMB. METHODS: We searched Ovid MEDLINE, Ovid Embase, Ovid CDR, Cochrane Central, Scopus, and Web of Science for studies where EAM was used for EMB. Data abstracted included demographics, indications, final diagnoses, histology findings, and technical details of biopsy extraction. Test characteristics including sensitivity (Se), specificity (Sp), and area under curve (AUC) were calculated on a per-patient and per-biopsy level. RESULTS: Seventeen studies (9 case series, 8 case reports) were included in this systematic review. EAM-guided EMB was performed in 148 patients and results of 207 individual biopsies were available for analysis. The most common indications for EAM-guided EMB were suspected arrhythmogenic right ventricular cardiomyopathy (ARVC), myocarditis, and cardiac sarcoidosis (CS). The pooled sensitivity and specificity for EAM-guided EMB for the diagnosis of cardiomyopathies (ARVC, myocarditis, CS, and other specific diagnoses) were 92 and 58% on per-biopsy analysis and 100 and 39% on per-patient analysis. Among the individual components of abnormal EGMs, abnormal unipolar EGM had the best AUC on per-biopsy (0.81, 95% CI 0.68-0.90) and per-patient analysis (0.84, 95% CI 0.68-0.92). EAM-guided EMB appears safe. Adverse events included 1 hemopericardium, 2 minimal asymptomatic pericardial effusions, and 1 femoral hematoma. CONCLUSIONS: EAM-guided EMB is a safe and efficacious method and might improve test characteristics over conventional fluoroscopy-guided biopsy.

No-fistula vs. fistula type anorectal malformation: Outcome comparative study.

INTRODUCTION: Anorectal malformation (ARM) is a congenital defect that exists in varying presentations and no-fistula type (NFT) ARM is a rare high-type category. We aim to report our experience with management of this anomaly and its outcome, compared to the more common fistula-type (FT) ARM. METHODS: A retrospective review of medical records of patients diagnosed with high ARM and 3years and older, for the period between September 2000 and January 2015 was conducted. Demographic, anatomic, and outcome data were obtained for each group and compared. Quality of life data were collected using the Krickenbeck classification and assessed as documented at clinic visits as well as phone interviews. RESULTS: There were 100 patients managed for ARM during that period and were 3years or older. Sixteen of them were NFT (16%). For comparison purposes each NFT patient was matched with 3 FT patients. We have analyzed data on 44 patients with FT (44 males), and 16 with NFT (12 males and 4 females). The occurrence of Down syndrome in NFT patients was 56.2% compared to 0% in the FT patients (p=<0.0001). Quality of Life data showed no significant differences between the two groups with p-values of 0.39, 1.0, and 1.0 for Voluntary Bowel Movement, Soiling, and Constipation respectively. CONCLUSION: NFT ARM represents a significant number at our population (16%). There is a strong association between NFT ARM and Down syndrome. NFT ARM has similar outcomes compared to the FT ARM. TYPE OF STUDY: Clinical research paper. LEVEL OF EVIDENCE: Level III.