Persistently abnormal device-detected thoracic impedance and OptiVol fluid index related to breast reconstruction surgery.

With significant correlation shown between intrathoracic impedance and intrathoracic fluid volume, the utility of OptiVol fluid index (Medtronic, Minneapolis, MN, USA) in the management of patients with heart failure has been well-described. Although intrathoracic impedance is mainly affected by the changes in the intrathoracic fluid volume, a "false-positive" OptiVol fluid index can occur in the absence of overt congestive heart failure. We present a case of false positive Optivol fluid index elevation in a woman following breast reconstruction surgery.

Acquired Gerbode Defect in a Patient With Infective Endocarditis of Bicuspid Aortic Valve.

Aortic valve abscess is a fatal complication of infective endocarditis. Transthoracic echocardiography is the initial imaging obtained in suspected infective endocarditis. However, its accuracy in detecting cardiac complications remains low, thus should be followed by transesophageal echocardiography if the clinical situation permits. Here, we present a case of a bicuspid aortic valve infective endocarditis caused by Streptococcus agalactiae and complicated with aortic valve abscess and acquired Gerbode defect, which appeared as a tricuspid valve vegetation on transthoracic echocardiography.

Cardiac Arrhythmias and COVID-19: Correlation With Disease Severity.

Background Cardiac arrhythmia is one of the life-threatening cardiovascular complications commonly reported in patients hospitalized with coronavirus disease 2019 (COVID-19). We aimed to evaluate the association between cardiac arrhythmias and disease severity based on oxygen requirement. Methods In this retrospective observational chart review-based study we recruited 396 patients hospitalized with COVID-19 from March 2020 to May 2020 from two regional medical centers in New Jersey, USA. Patients' baseline characteristics, secondary diagnoses, and laboratory findings were manually extracted and compared among two groups: patients with cardiac arrhythmias and those without. Poisson regression analysis was used to evaluate the correlation of cardiac arrhythmias and increased oxygen requirement, which are: room air (RA), nasal cannula (NC), high flow nasal cannula (HFNC), and bi-level positive airway pressure ventilation or invasive mechanical ventilation (BIPAP/MV). Results The demographic characteristics of the patients were: aged 61 +/- 18.7 years (mean +/- standard deviation); with 56% being male, and 44.9% of African American race. There were 16% patients on RA, 40% on NC, 15% on HFNC, and 29% on BIPAP/MV. The incidence of cardiac arrhythmias was 36.7% (20% pulseless electrical activity (PEA), 13.5% atrial fibrillation (AF). 56% of AF was new-onset arrhythmia. Compared to the RA group, the risk of cardiac arrhythmias was significantly higher in BIPAP/MV (OR 3.3; 95% CI 1.8 - 6.2, p <0.001) and HFNC (OR 2.9; 95% CI 1.5-5.7, p0.001), but not in NC group (OR 0.95; 95% CI 0.4-1.8, p0.89). Compared to patients without arrhythmias, patients with arrhythmias were older (mean age 71 vs. 56 years, p <0.001) and had more comorbidities (Charlson comorbidity index (CCI), 4.7 vs. 2.9, p <0.001). The continued therapy of angiotensin-converting enzyme inhibitors or angiotensin-II receptor blockers did not seem to be associated with increased or decreased risk of cardiac arrhythmias. Conclusion The incidence of cardiac arrhythmias among hospitalized COVID-19 patients was 36.7% with PEA being common in patients who succumbed to death, and AF in those patients who survived. The incidence of cardiac arrhythmias positively correlated with disease severity based on oxygen requirement and was higher among patients requiring HFNC or BIPAP/MV.

Traversing boundaries: thrombus in transit with paradoxical embolism.

A 72-year-old male is diagnosed with paradoxical embolus after he presented with concurrent deep vein thrombosis, stroke, and multiple arterial emboli in the presence of a patent foramen ovale (PFO). Paradoxical embolus requires the passage of a thrombus from the venous into the arterial circulation through a right-to-left shunt leading to systemic embolism. But, despite the high incidence of PFO (27.3% across all age groups by autopsy), paradoxical embolism (PDE) is uncommon, representing <2% of all arterial emboli. We present a case report where a thrombus has been directly observed passing through the PFO during an echocardiogram study; thus, clearly delineating the true cause of multiple thromboemboli and stoke in our patient. Subsequent Transesophageal Echocardiography (TEE) also interestingly showed the thrombus in transit in the aorta and pulmonary artery.

Beam profile disturbances from implantable pacemakers or implantable cardioverter-defibrillator interactions.

The medical community is advocating for progressive improvement in the design of implantable cardioverter-defibrillators and implantable pacemakers to accommodate elevations in dose limitation criteria. With advancement already made for magnetic resonance imaging compatibility in some, a greater need is present to inform the radiation oncologist and medical physicist regarding treatment planning beam profile changes when such devices are in the field of a therapeutic radiation beam. Treatment plan modeling was conducted to simulate effects induced by Medtronic, Inc.-manufactured devices on therapeutic radiation beams. As a continuation of grant-supported research, we show that radial and transverse open beam profiles of a medical accelerator were altered when compared with profiles resulting when implantable pacemakers and cardioverter-defibrillators are placed directly in the beam. Results are markedly different between the 2 devices in the axial plane and the sagittal planes. Vast differences are also presented for the therapeutic beams at 6-MV and 18-MV x-ray energies. Maximum changes in percentage depth dose are observed for the implantable cardioverter-defibrillator as 9.3% at 6 MV and 10.1% at 18 MV, with worst distance to agreement of isodose lines at 2.3 cm and 1.3 cm, respectively. For the implantable pacemaker, the maximum changes in percentage depth dose were observed as 10.7% at 6 MV and 6.9% at 18 MV, with worst distance to agreement of isodose lines at 2.5 cm and 1.9 cm, respectively. No differences were discernible for the defibrillation leads and the pacing lead.

Successful ablation of focal left atrial tachycardia using Stereotaxis Niobe remote magnetic navigation system.

Stereotaxis Niobe remote magnetic navigation system (MNS) (St Louise, USA), is a new technology that has applications in the field of catheter based ablation treatment of cardiac arrhythmias. Most if not all data on the feasibility, safety, and efficacy of the Stereotaxis Niobe MNS comes from select centres where highly skilled personnel have acquired considerable experience using this technology. Herein, we report a case where the Stereotaxis Niobe MNS was successfully used to perform remotely-controlled high density three-dimensional electroanatomical mapping and radiofrequency ablation of a focal atrial tachycardia originating from the anteroseptal region of the left atrium.

Verapamil-sensitive left posterior fascicular ventricular tachycardia after myocardial infarction.

Verapamil-sensitive fascicular ventricular tachycardia (VT) of right bundle branch block (RBBB) and superior axis pattern is typically seen in young patients with structurally normal hearts and considered "idiopathic". Recently, involvement of the Purkinje system in post-infarction monomorphic VT that mimics such idiopathic fascicular VT has been described. In this report we describe a case of a patient who following myocardial infarction developed left posterior fascicular Purkinje reentrant VT that was sensitive to verapamil. The VT was successfully treated by radiofrequency ablation guided by three dimensional electroanatomical CARTO mapping. Our case highlights that involvement of Purkinje fibers should be considered in post infarction patients with VT of narrow QRS duration, RBBB morphology and superior axis. Recognition of such VT is clinically important, as this arrhythmia is amenable to curative catheter ablation.

Hypoxemia after implantation of a permanent pacemaker.

We describe a case in which the patient developed profound, intermittent hypoxemia after implantation of a permanent pacemaker and subsequently after revision of its leads. Cardiac catheterization demonstrated right-to-left shunting at the level of the atria in the presence of a patent foramen ovale that required closure, resulting in the resolution of symptoms. Our report highlights the fact that the presence of a patent foramen ovale with intermittent right-to-left shunting should be considered in a differential diagnosis of hypoxemia after implantation of heart rhythm devices.

Electrical storm of monomorphic ventricular tachycardia after a cardiac-resynchronization-therapy-defibrillator upgrade.

In patients with significant left ventricular dysfunction and congestive heart failure despite optimal medical therapy, implantation of cardiac resynchronization therapy-defibrillation (CRT-D) devices has been shown to improve symptoms and mortality. In this report, we describe a case of a patient with ischaemic cardiomyopathy who developed incessant ventricular tachycardia (VT) after undergoing an upgrade from an implantable cardioverter defibrillator to a CRT-D device. The patient required multiple anti-arrhythmic agents, removal of the coronary sinus lead, and radiofrequency ablation to control VT. Thus, in rare patients, the CRT devices may potentially cause 'proarrhythmia' with serious consequences.

Marked QT prolongation and torsades de pointes secondary to acute ischemia in an elderly man taking dofetilide for atrial fibrillation: a cautionary tale.

Dofetilide has been shown to be effective and safe in maintaining sinus rhythm in patients with persistent atrial fibrillation and congestive heart failure. Because of serious side effects of an increase in the QT interval causing torsades de pointes, dofetilide must be initiated with close monitoring of the QT interval in an inpatient setting. However, little has been reported about conditions surrounding the change in QT interval after the steady state is achieved that may have implications in the safety and efficacy of the drug. We report marked QT prolongation and torsades de pointes in a setting of flash pulmonary edema resulting from acute myocardial ischemia in a patient who was being treated with dofetilide for atrial fibrillation. Our case reminds the clinicians that the adverse and proarrhythmic effects of dofetilide can occur due to changes in the arrhythmic substrate during acute severe ischemia.

Anticoagulation in nonvalvular atrial fibrillation.

Atrial fibrillation is the most common, serious, cardiac arrhythmia and increases the risk for ischemic stroke fivefold. Nonvalvular atrial fibrillation may be responsible for up to 15-20% of strokes. Antiplatelet agents and oral anticoagulants are used for stroke prevention in atrial fibrillation. The following review article discusses the potential risks and benefits of oral anticoagulants in nonvalvular atrial fibrillation with particular emphasis on accurate risk stratification tools for ischemic stroke.