Inter-atrial septal balloon dilation to facilitate intracardiac echocardiography guided left atrial appendage occlusion.

INTRODUCTION: Percutaneous left atrial appendage occlusion (LAAO) is traditionally performed under general anesthesia with trans-esophageal echocardiography guidance. Intracardiac echo (ICE)-guided LAAO closure is increasing in clinical use. The ICE catheter is crossed into LA via interatrial septum (IAS) after the septum is dilated with LAAO delivery sheath. This step can be time-consuming and requires significant ICE catheter manipulation, which increases the risk of cardiac perforation. Pre-emptive septal balloon dilation can potentially help with ICE advancement in the LA. We sought to evaluate the effect of pre-dilation of the IAS with an 8 mm balloon on the ease of crossing the ICE catheter, fluoroscopy time for crossing, and overall procedure time. METHODS: The Piedmont LAAO registry was used to identify consecutive patients who underwent LAAO. The initial 25 patients in whom balloon dilation of the IAS was performed served as the experimental cohort, and the 25 consecutive patients before that in whom balloon dilation was not performed served as controls. In the experimental group, after a trans-septal puncture, the sheath was retracted to the right atrium with a guidewire still in the LA. An 8 × 40 mm Evercoss™ over the wire balloon was inflated across the IAS. The ICE catheter was then crossed into the LA using the fluoroscopic landmark of the guide wire and the ICE imaging. The sheath was then advanced along the ICE catheter via the transseptal puncture (TSP) and the procedure continued. Follow-up compputed tomography imaging was obtained at 4-8 weeks. RESULTS: Each group consisted of 25 patients. There were no significant differences in baseline characteristics. All procedures were performed successfully under conscious sedation and ICE guidance. There was a significant reduction in the overall procedure time, fluoroscopy time, and time for transseptal puncture to ICE in LA. There was no difference in the size of the acute residual interatrial shunt, as measured via ICE, or the size and presence of iatrogenic ASD at follow-up. CONCLUSION: Balloon dilation of TSP is safe and is associated with increased efficiency in ICE-guided LAAO procedures.

Subcutaneous implantable cardioverter-defibrillator electrode fracture: Follow-up, troubleshooting, and evaluation.

The subcutaneous-implantable cardioverter-defibrillator (S-ICD) and its electrode were developed to avoid long-term complications of transvenous leads in the vasculature. We report a case of unexpected, inappropriate S-ICD shocks due to oversensing of high-amplitude, nonphysiologic, electrical noise artifacts that were not preceded by high-impedance alerts or sensing electrogram noise detections. Following explant, high-magnification X-ray imaging of the S-ICD electrode demonstrated partial fracture of the distal sensing conductor located near a short radius bend in the electrode at the electrode-header interface. Clinicians should be aware of a potential for fatigue failure fracture of the S-ICD electrode. Recommendations for systematic S-ICD follow-up and troubleshooting are discussed.

Renal Dysfunction following Direct Current Cardioversion of Atrial Fibrillation: Incidence and Risk Factors.

INTRODUCTION: Emerging data suggest that cardioversion for atrial fibrillation (AF) may be associated with acute kidney injury (AKI). However, limited data are available regarding the incidence and risk factors for AKI after direct current cardioversion (DCCV) of AF. METHODS: All patients undergoing DCCV at Mayo Clinic between 2001 and 2012 for AF were prospectively enrolled in a database. All patients with serum creatinine (SCR) values pre- and post-cardioversion were reviewed for AKI, defined as a ≥25% decline in eGFR (estimated glomerular filtration rate) from baseline value within 7 days of the DCCV. RESULTS: Of the 6,427 eligible patients, 1,256 (19.5%) patients had pre- and post-DCCV SCR available and formed the cohort under study. The mean age was 70.4 (SD 11.7) years, and 67.3% were male. During the study period, 131 (10.4%) patients suffered from AKI following DCCV. AKI was independently associated with inpatient status (OR 26.79; 95% CI 3.69-194.52), CHA2DS2-VASc score (OR 1.25; 95% CI 1.11-1.41), prior use of diuretics (OR 1.59; 95% CI 1.03-2.46), and absence of CKD (OR 1.61; 95% CI 1.04-2.49), and was independent of the success of the DCCV. None of the patients required acute dialysis during the study outcome period. CONCLUSION: AKI following DCCV of AF is common, self-limited, and without the need for replacement therapies.

LV only pacing-mediated electrical storm with cardiac resynchronization therapy managed by simultaneous biventricular pacing.

Ventricular arrhythmia (VA) is a rare complication of cardiac resynchronization therapy (CRT). Little is known about ventricular proarrhythmia related to the pacing vector of CRT. This case report describes the elimination of ventricular arrythmia using biventricular pacing in a patient with VT-storm related to LV only pacing as part of the AdaptivCRT algorithm (Medtronic Inc). Simultaneous biventricular pacing was effective in eliminating polymorphic ventricular tachycardia. Changing the pacing vector is a noninvasive treatment strategy that should be considered to manage VA due to CRT.

Fibroplasty (venoplasty) to facilitate transvenous lead placement: A single-center experience.

INTRODUCTION: Venous stenosis is a well-recognized complication of transvenous leads (TVLs) that is encountered during lead revisions or device upgrades. We here report the outcomes of TVL placement facilitated by fibroplasty or tunneling (TUN) procedure. METHODS: We conducted a single-center retrospective cohort study of all patients undergoing TVL implantation requiring fibroplasty or TUN from 2005 to 2017. Medical records and procedure reports were reviewed for relevant data. Outcomes for fibroplasty and TUN to facilitate TVL placement were compared. RESULTS: Sixty patients had fibroplasty and thirty-five patients had a TUN procedure. There was no difference in procedure success rates between the two groups (97% fibroplasty vs. 100% TUN; p = .98). The fluoroscopy time was longer (fibroplasty = 39.7 ± 21.5 min vs. TUN = 29.2 ± 21.3 min; p = .01) and the total procedural time was shorter in the fibroplasty group (fibroplasty = 247 ± 77.8 min vs. TUN = 287 ± 77.1 min; p = .01). TUN was associated with a significantly higher incidence of acute complications (fibroplasty = 0 vs. TUN = 8; p = .002) most requiring invasive intervention and/or transfusion with blood products. Long-term complications requiring additional device-related procedures were comparable between the two groups (fibroplasty = 6 vs. TUN = 6; logrank p = .21). CONCLUSIONS: For patients with venous stenosis requiring additional TVL, balloon fibroplasty is associated with similar rates of success and a significantly decreased incidence of acute complications when compared with subcutaneous TUN.

Defining the substrate for ventricular tachycardia ablation: The impact of rhythm at the time of mapping.

BACKGROUND: Voltage mapping is critical to define substrate during ablation. In ventricular tachycardia, abnormal potentials may be targets. However, wavefront of activation could impact local signal characteristics. This may be particularly true when comparing sinus rhythm versus paced rhythms. We sought to determine how activation wavefront impacts electrogram characteristics. METHODS: Patients with ischemic cardiomyopathy, ventricular tachycardia, and without fascicular or bundle branch block were included. Point by point mapping was done and at each point, one was obtained during an atrial paced rhythm and one during a right ventricular paced rhythm. Signals were adjudicated after ablation to define late potentials, fractionated potentials, and quantify local voltage. Areas of abnormal voltage (defined as <1.5 mV) were also determined. RESULTS: 9 patients were included (age 61.3 ± 9.2 years, 56% male, mean LVEF 34.9 ± 8.6%). LV endocardium was mapped with an average 375 ± 53 points/rhythm. Late potentials were more frequent during right ventricular pacing (51 ± 21 versus 32 ± 15, p < 0.01) while overall scar area was higher during atrial pacing (22 ± 11% vs 13 ± 7%, p < 0.05). In 1/9 patients, abnormal potentials were seen during a right ventricular paced rhythm that were not apparent in an atrial paced rhythm, ablation of which resulted in non-inducibility. CONCLUSION: Rhythm in which mapping is performed has an impact on electrogram characteristics. Whether one rhythm is preferable to map in remains to be determined. However, it is possible defining local signals during normal conduction as well as variable paced rhythms may impart a greater likelihood of elucidating arrhythmogenic substrate.

Safety of thoracic magnetic resonance imaging for patients with pacemakers and defibrillators.

BACKGROUND: During magnetic resonance imaging (MRI), cardiac implantable electronic device (CIED) leads can be antennae to focus energy onto myocardium, leading to heating and arrhythmias. Clinical data on thoracic MRI safety for patients with legacy devices are limited. OBJECTIVE: The purpose of this study was to identify patients undergoing thoracic MRI with legacy devices, compare the incidence of adverse events of those patients with control patients undergoing brain MRI with legacy devices, and compare paired cardiac troponin T (cTnT) values. METHODS: In this single-center study, we reviewed a prospectively collected database of patients with CIED undergoing MRI from January 25, 2008, through February 28, 2017. RESULTS: Of 952 patients (1290 scans), 120 patients (12.6%) underwent 134 thoracic MRI scans with legacy CIEDs (median [range] age 61.98 [21.24-86.96] years; male 71.1%). Median (range; interquartile range [IQR]) age of leads across devices was 3.5 (1.6-7.1; 5.5) years; implantable cardioverter-defibrillators (ICDs) were oldest (median [range; IQR], 3.7 [1.1-8.0; 6.9] years). No difference was observed in incidence of adverse events between groups. Paired cTnT values were compared for 19 patients (19 scans) with no difference between pre- and postimaging values. No significant difference was present in device setting values before and after MRI (mean follow-up 72.5 days). Incidence of adverse events was no different after adjustment for ICD coil number. CONCLUSION: Thoracic MRI is relatively safe in an institutional multidisciplinary program. It does not represent greater risk than brain MRI for patients with legacy CIEDs.

Radiofrequency ablation of the cavotricuspid isthmus for management of atrial flutter in patients with congenital heart disease after tricuspid valve surgery: A single-center experience.

BACKGROUND: Typical atrial flutter involving the cavotricuspid isthmus (CTI) is the most common reentrant arrhythmia in congenital heart disease and ablation is effective in its management. However, congenital heart disease patients often require surgical interventions on their tricuspid valve that utilize prosthetic material, making CTI ablation technically challenging. OBJECTIVE: To describe the techniques and outcomes of CTI ablation in the presence of prior tricuspid valve repair or replacement. METHODS: We included all patients who had undergone tricuspid valve repair utilizing an annuloplasty ring or tricuspid valve replacement who underwent CTI ablation for treatment of atrial arrhythmias between 2005 and 2017. Acute procedural success was defined as demonstration of bidirectional conduction block across the CTI. Long-term success was defined as lack of arrhythmia recurrence on monitoring or related symptoms. RESULTS: Sixteen patients met the inclusion criteria. Twelve (75%) patients had Ebstein's anomaly, 14 (88%) patients had a prosthetic tricuspid valve, and 2 (12%) patients had annuloplasty ring. Acute success was achieved in all cases, with no complications. Radiofrequency ablation was required on the ventricular side in 9 (56%) patients. In 1 case, ablation in the small cardiac vein was required. All patients remained free from atrial flutter during 18 months follow-up (range, 1-101 months). CONCLUSION: Our study demonstrates the safety and efficacy of catheter ablation of the CTI in the presence of a tricuspid annuloplasty ring or a prosthetic tricuspid valve. This may require ablation from the ventricular side of the valve to target atrial tissue rendered inaccessible as a result of tricuspid valve surgery.

Feasibility and safety of percutaneous epicardial access for mapping and ablation for ventricular arrhythmias in patients on oral anticoagulants.

PURPOSE: This study aimed to assess the risk of procedure-related complications of percutaneous epicardial access (EpiAcc) for radiofrequency catheter ablation (RFA) of ventricular arrhythmias (VAs) in patients chronically treated oral anticoagulants (OACs) with warfarin compared to those not on OACs. METHODS: We analyzed 205 patients (53 ± 16 years, 155 males) undergoing percutaneous EpiAcc as part of an RFA for VAs, and compared the outcome between patients chronically on OACs with warfarin (OAC group) and those without (non-OAC group). RESULTS: Forty-seven patients (23%) were chronically treated on OACs before their procedure. EpiAcc in patients on OAC (OAC group) was not associated with an increased risk of cardiac tamponade (11% vs. 6%, p = 0.238) compared to non-OAC group, but a higher risk of need for blood transfusion (17% vs. 6%; p = 0.013). With respect to the OAC group, the international normalized ratio (INR) on the day of the RFA was ≥ 2.0 in 9 patients (19%) and < 2.0 in the remaining 38 patients (81%). The rate of all complication and blood transfusion were similar between them (11% vs. 21%; p = 0.496, 11% vs. 18%; p = 0.600). CONCLUSION: Percutaneous EpiAcc in patients on chronic OAC with warfarin did not significantly increase the risk of cardiac tamponade, but was associated with a higher risk of need for blood transfusion. EpiACC in patients with an INR > 2.0 is reasonable in experienced hands when clinical indications are strong.

Safety of magnetic resonance imaging in patients with legacy pacemakers and defibrillators and abandoned leads.

BACKGROUND: During magnetic resonance imaging (MRI), abandoned leads may act as antennae that result in tissue heating and arrhythmia induction. OBJECTIVE: The purpose of this study was to assess the safety of MRI in patients with abandoned leads, with the addition of cardiac troponin T (cTnT) assessment to screen for myocardial damage. METHODS: We reviewed our prospectively collected database of patients with cardiovascular implantable electronic devices (CIEDs) undergoing MRI between 2008 and 2017 at Mayo Clinic, Rochester, MN, and selected patients who had abandoned leads. We compared the adverse events in this population with an age, sex, and site of MRI-matched cohort of patients selected from this database. We evaluated paired (before/after) cTnT values using MRI in these patients. RESULTS: Of 952 patients, 80 (8.4%) underwent 97 MRI scans with CIEDs in situ with 90 abandoned leads in place during the scans. The median age was 66 years (interquartile range 22.3 years) 66.1 years (interquartile range, Q1,Q3: 53.6, 75.9) with 66.3% (53 patients) men. There was no clinical or electrical evidence of CIED dysfunction, arrhythmias, or pain. Paired samples for the measurement of cTnT values were available in 40 patients undergoing 44 MRI examinations. The mean difference between the pre- and postimaging values was -0.002 ± 0.006 ng/mL (interquartile range 0). There was no difference after adjustment for total number of leads per patient and total number of implantable cardioverter-defibrillator coils. CONCLUSION: There was no evidence of myocardial injury as measured by paired cTnT. The risk of MRI with abandoned leads appears low, suggesting a favorable risk-benefit profile in patients with CIEDs and abandoned leads who are considered for MRI.

EFFECTS OF RAMADAN FASTING ON BLOOD PRESSURE IN NORMOTENSIVE MALES.

BACKGROUND: Research has been done to investigate the effect of intermittent complete fasting on human physiological parameters but the effect of fasting on blood pressure remains relatively unexplored. Research in animal models suggests a hypotensive effect with an undetermined mechanism. Muslims worldwide fast daily from dawn to dusk throughout the Islamic month of Ramadan. This study was to investigate the proposed hypotensive effect of Ramadan fasting in males over A period of 20 days and to study the relationship of the pattern of blood pressure variation with body mass index change. METHODS: A repeated measures observational study design was implemented with convenient sampling. Study group included 40 normotensive, non-smoker males with no known comorbidities between the ages of 18-40 who fasted daily in the month of Ramadan. One set of BP readings, each, was taken one week before the start of Ramadan and on the 7th, 14th and 21st day of Ramadan which included pre and post Iftar measurements along with other variables. Data was analysed by repeated measures ANOVA using SPSS. The differences were compared with critical values generated by Tukey's Method. RESULTS: There was a significant drop in systolic BP of 7.61 mmHg before Iftar, 2.72 mm-Hg after Iftar (p<0.005). There was a significant effect of Ramadan on diastolic BP (p<0.005), the drop being 3.19 mmHg. The drop in body mass index was significant only before Iftar at 0.3 kg/m2 (p<0.005). Pulse rate showed a significant drop of 7.79 bpm before Iftar and a significant rise of 3.96 bpm (p<0.005). CONCLUSIONS: Intermittent fasting causes a drop in both systolic and diastolic blood pressure in normotensive males.

Lesion-specific differences for implantable cardioverter defibrillator therapies in adults with congenital heart disease.

BACKGROUND: Sudden cardiac death is a major cause of late mortality in adults with congenital heart disease (ACHD). While data exist for adults with repaired Tetralogy of Fallot (TOF), little is known about those with non-TOF lesions. We examined the relative rates in implantable cardioverter defibrillator (ICD) therapy according to congenital lesion type in a large-volume adult congenital heart center. METHODS: A cohort of 59 individuals (median follow up time, 3.2 years range 0-10) with ACHD and ICDs was stratified according to underlying congenital lesion and implant indication. Appropriate therapies were defined as any therapy for a physician-adjudicated ventricular arrhythmia. Rates of inappropriate and appropriate ICD therapies were analyzed according to several relevant clinical variables. RESULTS: Thirty-three (56%) TOF, 15 (25.4%) L- or D-transposition of great arteries, and 11 (18.6%) with other lesions were included in the analysis. Approximately half (52.5%) were implanted for primary prevention indications. During follow-up, 12 (20.3%) patients received appropriate ICD therapies and 13 (22%) patients received inappropriate therapies. The incidence of appropriate shocks among patients with TOF was 27.3% (9/33) compared to 11.5% (3/26) among non-TOF diagnoses during the follow-up time (p = 0.043). CONCLUSIONS: ACHD patients with non-TOF congenital lesions are significantly less likely to receive appropriate ICD therapy than those with TOF. Our analysis calls into question the validity of traditional ICD implantation guidelines in this growing and diverse patient population.

Plasma exchange for severe hypertriglyceridemia-induced pancreatitis in an orthotopic heart transplant recipient.

We here report a 33-year old male with diabetes, hypertension and history of orthotopic heart transplantation treated by plasma exchange for severe HTG (hypertriglyceridemia) induced pancreatitis. At the time of presentation, his serum TG (triglyceride) level was 10,278 mg/dL. He underwent one of the three planned sessions of plasma exchange, resulting in a decrease in TG level from 4728 mg/dL to 1708 mg/dL. The hospital course was complicated with shock, hemorrhagic transformation of the pancreatitis and acute respiratory distress syndrome. This prevented any further plasma exchange sessions. He was subsequently discharged home in a stable state and TG level of 80 mg/dL. Plasma exchange can be safely used to manage HTG induced pancreatitis in heart transplant recipients.

Prevalence of mistreatment or belittlement among medical students--a cross sectional survey at a private medical school in Karachi, Pakistan.

BACKGROUND: Mistreatment or belittlement of medical students either by faculty or fellow students has often been reported. Perception of mistreatment has also been associated with increased degree of psychological morbidity. There is a lack of such studies being conducted amongst the medical students of Pakistan. The aim of this study was to determine the prevalence and forms of perceived mistreatment and presence of mental health morbidity in a private medical school in Pakistan. Also, any association between mental health morbidity and mistreatment was to be identified. METHODS: A cross sectional study was carried out on medical students from Aga Khan University Hospital, Karachi, Pakistan during the period of June-September 2007. A self administered questionnaire, adapted from Frank et al and Baldwin et al was distributed to a total of 350 students. The questionnaire consisted of three parts: the first dealing with the demographics of the population, the second concerning the various forms of mistreatment, while the third assessed the mental health of students using the General Health Questionnaire 12(GHQ12). Descriptive statistics were performed. The Chi-square test and Fisher's exact tests were applied. RESULTS: A total of 350 students were approached out of which 232 completed the questionnaire giving a response rate of 66.2%. Mistreatment was reported by 62.5% (145/232) of the respondents. Of these, 69.7% (83/145) were males and 54.9% (62/145) were females. There was a significant relationship between gender, year division, stress at medical school and possible use of drugs/alcohol and reported mistreatment but no statistical relationship was seen with psychiatric morbidity. The overall prevalence of psychological morbidity was 34.8% (77/221). CONCLUSION: This study suggests high prevalence of perceived mistreatment and psychological morbidity among Pakistani medical students. However, no association was found between these two aspects of medical student education. There is a need to bring about changes to make the medical education environment conducive to learning. Increased student feedback, support systems and guidance about progress throughout the year and the provision of adequate learning resources may provide help with resolving both of these issues.

On pump coronary surgical revascularization in a patient with chronic immune thrombocytopenic purpura.

We performed on-pump coronary artery bypass graft surgery on a 54-year-old female, known case of chronic Idiopathic Thrombocytopenic Purpura (ITP), hypertension and dyslipidaemia who had presented to us with progressive exertional shortness of breath and chest pain. The decision of going on with CABG was made after two weeks of preoperative treatment with prednisolone. Her platelet counts pre-operatively and on the 4th post-operative day were 135 x 10(9)/L and 32 x 10(9)/L. She had an unremarkable post-operative recovery, without requiring whole blood or platelet transfusions. We recommend preoperative steroid treatment in patients with chronic ITP undergoing CABG.