Artificial Intelligence for the Detection and Treatment of Atrial Fibrillation.

AF is the most common clinically relevant cardiac arrhythmia associated with multiple comorbidities, cardiovascular complications (e.g. stroke) and increased mortality. As artificial intelligence (AI) continues to transform the practice of medicine, this review article highlights specific applications of AI for the screening, diagnosis and treatment of AF. Routinely used digital devices and diagnostic technology have been significantly enhanced by these AI algorithms, increasing the potential for large-scale population-based screening and improved diagnostic assessments. These technologies have similarly impacted the treatment pathway of AF, identifying patients who may benefit from specific therapeutic interventions. While the application of AI to the diagnostic and therapeutic pathway of AF has been tremendously successful, the pitfalls and limitations of these algorithms must be thoroughly considered. Overall, the multifaceted applications of AI for AF are a hallmark of this emerging era of medicine.

Mechanical thrombectomy versus catheter directed thrombolysis in patients with pulmonary embolism: A multicenter experience.

OBJECTIVES: Compare in-hospital outcomes of patients treated with either mechanical thrombectomy (MT) or catheter directed lysis (CDL) in treatment of acute pulmonary embolism (PE). METHODS: This is a multicenter, retrospective cohort study of patients undergoing MT or CDL for acute PE between 2014 and 2021. The primary outcome was the composite of in-hospital death, significant bleed, vascular complication, or need for mechanical support post-procedure. Secondary outcomes included the individual components of the composite outcome in addition to blood transfusions, invasive hemodynamics, echocardiographic data, and intensive care unit (ICU) utilization. RESULTS: 458 patients were treated for PE with 266 patients in the CDL arm and 192 patients in the MT arm. The primary composite endpoint was not significantly different between the two groups with CDL 12% versus MT 11% (p = 0.5). There was a significant difference in total length of ICU time required with more in the CDL group versus MT (3.8 ± 2.0 vs. 2.8 ± 3.0 days, p = 0.009). All other secondary end points showed no significant difference between the groups. CONCLUSIONS: In patients undergoing catheter directed treatment of PE, there was no difference between MT and CDL in terms of in-hospital mortality, bleeds, catheter-related complications, and hemodynamics.

Long Term Follow-Up of Stereotactic Body Radiation Therapy for Refractory Ventricular Tachycardia in Advanced Heart Failure Patients.

Background: Initial studies of stereotactic body radiation therapy (SBRT) for refractory ventricular tachycardia (VT) have demonstrated impressive efficacy. Follow-up analyses have found mixed results and the role of SBRT for refractory VT remains unclear. We performed palliative, cardiac radio ablation in patients with ventricular tachycardia refractory to ablation and medical management. Methods: Arrhythmogenic regions were targeted by combining computed tomography imaging with electrophysiologic mapping with collaboration from a radiation oncologist, electrophysiologist and cardiac imaging specialist. Patients were treated with a single fraction 25 Gy. Total durations of VT, the quantity of antitachycardia pacing (ATP) and shocks before and after treatment as recorded by implantable cardioverter-defibrillators (ICDs) were analyzed. Follow-up extended until most recent device interrogation unless transplant, death or repeat ablation occurred sooner. Results: Fourteen patients (age 50-78, four females) were treated and had an average of two prior ablations. Nine had ACC/AHA Stage D heart failure and three had left ventricular assist devices (LVAD). Two patients died shortly after SBRT, one received a prompt heart transplant and another had significant VT durations in the following months that were inaccurately recorded by their device. Ten of the 14 patients remained with adequate data post SBRT for analysis with an average follow-up duration of 216 days. Seven of those 10 patients had a decrease in VT post SBRT. Comparing the 90 days before treatment to cumulative follow-up, patients had a 59% reduction in VT, 39% reduction in ATP and a 60% reduction in shocks. Four patients received repeat ablation following SBRT. Pneumonitis was the only complication, occurring in four of the fourteen patients. Conclusion: SBRT may have value in advanced heart failure patients with refractory VT acutely but the utility over long-term follow-up appears modest. Prospective randomized data is needed to better clarify the role of SBRT in managing refractory VT.

Hands-on defibrillation with safety drapes: Analysis of compressions and an alternate current pathway.

BACKGROUND: Hands-on defibrillation (HOD) could theoretically improve the efficacy of cardiopulmonary resuscitation (CPR) though a few mechanisms. Polyethylene drapes could potentially facilitate safe HOD, but questions remain about the effects of CPR on polyethylene's conductance and the magnitude of current looping through rescuers' arms in contact with patients. METHODS: This study measured the leakage current through 2 mil (0.002 in.) polyethylene through two different current pathways before and after 30 min of continuous compressions on a CPR mannequin. The two pathways analyzed were the standardized IEC (International Electrotechnical Commission) leakage current analysis and a setup analyzing a current pathway looping through a rescuer's arms and returning to the patient. First, ten measurements involving the two pathways were obtained on a single polyethylene drape. 30 min of continuous compressions were applied to the drape on a CPR mannequin after which the ten measurements were repeated. RESULTS: Twenty patients undergoing elective cardioversion for atrial fibrillation (18/20) or atrial flutter (2/20) at Emory University Hospital underwent analysis all receiving 200 J shocks (age 38-101, 35% female). Through the IEC measurement method the peak leakage current mean was 0.70 +/- 0.02 mA before compressions and 0.59 +/- 0.19 mA after compressions. Only three of the ten measurements assessing current passing through a rescuer's arms had detectable current and each was of low magnitude. All measurements were well below the maximum IEC recommendations of 3.5 mA RMS and 5.0 mA peak. CONCLUSIONS: Polyethylene may facilitate safe HOD even after long durations of compressions. Current looping through a rescuer's arms is likely of insignificant magnitude.

Droxidopa as an effective treatment for refractory neurogenic orthostatic hypotension and reflex bradycardia in amyloid light-chain amyloidosis: a case report.

BACKGROUND: Droxidopa is an oral treatment for the stepwise treatment of neurogenic orthostatic hypotension from autonomic dysfunction. It has been shown to be useful predominantly with neurogenic orthostatic hypotension secondary to Parkinson's disease, but only a few cases have documented its usefulness in patients with neurogenic orthostatic hypotension due to amyloidosis, which is often severe and refractory. In addition, only one source in the literature reports the concomitant use of midodrine and droxidopa for such patients. Finally, we argue that droxidopa seems to have a protective effect against episodes of reflex bradycardia, which is not previously reported. CASE PRESENTATION: A 64-year-old white man was admitted for 1 year of worsening syncopal episodes, diarrhea, failure to thrive, heart failure, and neuropathy. Medical emergencies were called five times on the overhead hospital intercom over a 4-day period in the beginning of his admission due to severe hypotension and bradycardia. He was eventually diagnosed as having amyloid light-chain amyloidosis and myeloma. After starting droxidopa, both his systolic blood pressure and reflex bradycardia improved, and no more medical emergency events were called during the remaining 30 days of admission. He felt much better subjectively and was able to sit upright and engage in physical therapy. CONCLUSIONS: We show that droxidopa is effective when used with midodrine to treat refractory neurogenic orthostatic hypotension in patients with amyloidosis. There are very few cases reporting the use of droxidopa in amyloidosis, with only one study that uses droxidopa and midodrine concomitantly. In addition, our patient's reflex bradycardia improved drastically after starting droxidopa, which we believe is mediated by increased systemic norepinephrine. There were no side effects to droxidopa, and the benefits lasted well beyond the reported duration of 1-2 weeks that was noted to be a limitation in some studies.

Clinical experience of stereotactic body radiation for refractory ventricular tachycardia in advanced heart failure patients.

BACKGROUND: Stereotactic body radiation therapy (SBRT) has been shown to be effective in treating patients with refractory ventricular tachycardia. OBJECTIVE: The purpose of this study was to describe outcomes for SBRT in advanced heart failure patients admitted for repeated implantable cardioverter-defibrillator (ICD) therapies who were refractory to standard treatments. METHODS: SBRT simulation, planning, and treatments were performed using standard techniques with collaboration from a radiation oncologist, electrophysiologist, and cardiac imaging specialist. Patients were treated with single-fraction 25 Gy while awake. Efficacy was assessed by total durations in seconds of ventricular tachycardia, frequency of antitachycardia pacing (ATP), and quantity of shocks before and after treatment as recorded by an ICD. RESULTS: A total of 10 patients (mean age 61 years; 3 female) were included. Etiologies of heart failure were ischemic in 40% (4/10) and nonischemic in 60% (6/10). Among 8 patients with available ICD data, the total reduction in seconds of detected VT was 69% (pretreatment 1065 seconds/month vs posttreatment 332 seconds/month). The total reduction in ATP sequences was 48% (17.3 pretreatment and 8.9 posttreatment). Reduction in total ICD shocks after SBRT was 68% (2.9 shocks/month pretreatment and 0.9 shocks/month posttreatment). When excluding a single nonresponder, there was a significant reduction in VT seconds (94%; P = .04) and a trend toward ICD shock reduction (90%; P = .07) post-SBRT. CONCLUSION: Noninvasive treatment with SBRT was feasible and modestly effective at reducing VT burden in the critically ill. This suggests that SBRT treatment may be a useful palliation for electrical storm.

Hands-on defibrillation with a safety barrier: An analysis of potential risk to rescuers.

BACKGROUND: Interruptions in compressions reducethe efficacy of cardiopulmonary resuscitation (CPR) and are inevitable during hands-off periods for shocks. Clinical exam gloves were found to facilitate safe contact with patients during shock delivery but the safety of this practice has been questioned. Polyethylene is of interest because of its safety record in the medical arena and its electrical insulation properties. METHODS: This study measured the current leak through 2 mil (0.002 inch) polyethylene drapes during shock delivery. The current leak was assessed by measurement of voltage changes in a circuit recommended by the International Electrotechnical Commission (IEC) for current leak safety testing. Current flowed off the drape, through the circuit and to electric ground in a manner consistent with standardized testing. Perceptibility was assessed in a subset with the investigator's bare hands pressed into the drape during shock delivery. RESULTS: Thirty-three patients undergoing elective cardioversion at Emory University Hospital underwent analysis (age 23-90, 36% female). Biphasic energies were 200-360 J. The root mean square (RMS) current leak averaged 0.072 ± 0.022 mA and peak current leak averaged 0.67 ± 0.21 which is well below IEC recommendations of 3.5 mA RMS and 5.0 mA peak. Finally, no instances of dielectric breakdown occurred and no shocks were perceptible. CONCLUSIONS: Polyethylene is a common medical material which may facilitate safe hands-on defibrillation. Our data illustrates that a thin, semitransparent layer of polyethylene is a safe and feasible adjunct to cardiac arrest kits to allow continued compressions and simplification of the CPR process.