Publications by authors named "Susan B Mikell"

Objective: Asthma is a common disease which places significant burden on the US healthcare system and which can be associated with significant patient morbidity and mortality. Current medical therapies are costly and not curative. A new approach for a more permanent asthma treatment is the use of radiofrequency ablation.

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Introduction: Epicardial cardiac resynchronization therapy (CRT) permits unrestricted electrode positioning. However, this requires surgical placement of device leads and the risk of unwanted phrenic nerve stimulation. We hypothesized that shielded electrodes can capture myocardium without extracardiac stimulation.

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Objective: Pharmacotherapy for epilepsy is limited with 30% of patients refractory to this approach of suppressing seizures. Current surgical options are invasive and carry significant morbidities including infection, bleeding, and the potential for deleterious neurocognitive effects. As a result, there is a burgeoning need for innovation to develop safer and efficacious interventions.

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Background: Endocardial ablation of atrial ganglionated plexi (GP) has been described for treatment of atrial fibrillation (AF). Our objective in this study was to develop percutaneous epicardial GP ablation in a canine model using novel energy sources and catheters.

Methods: Phase 1: The efficacy of several modalities to ablate the GP was tested in an open chest canine model (n = 10).

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Introduction: The dominant location of electrical triggers for initiating atrial fibrillation (AF) originates from the muscle sleeves inside pulmonary veins (PVs). Currently, radiofrequency ablation (RFA) is performed outside of the PVs to isolate, rather than directly ablate these tissues, due to the risk of intraluminal PV stenosis.

Methods: In 4 chronic canine experiments, we performed direct PV muscle sleeve RFA ± postablation drug-coated balloon (DCB) treatment with paclitaxel/everolimus.

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Debulking of electrically active atrial tissue may reduce the mass of fibrillating tissue during atrial fibrillation, eliminate triggers, and promote maintenance of normal sinus rhythm (NSR). We investigated whether left atrial appendage (LAA) ligation results in modification of atrial electrical substrate. Healthy male mongrel dogs (N = 20) underwent percutaneous epicardial LAA ligation.

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Objective: To determine if ECG repolarization measures can be used to detect small changes in serum potassium levels in hemodialysis patients.

Patients And Methods: Signal-averaged ECGs were obtained from standard ECG leads in 12 patients before, during, and after dialysis. Based on physiological considerations, five repolarization-related ECG measures were chosen and automatically extracted for analysis: the slope of the T wave downstroke (T right slope), the amplitude of the T wave (T amplitude), the center of gravity (COG) of the T wave (T COG), the ratio of the amplitude of the T wave to amplitude of the R wave (T/R amplitude), and the center of gravity of the last 25% of the area under the T wave curve (T4 COG) (Fig.

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Pulmonary vein isolation is an established therapeutic procedure for symptomatic atrial fibrillation (AF). This approach involves ablation of atrial tissue just outside the pulmonary veins. However, patient outcomes are limited because of a high rate of arrhythmia recurrence.

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Background: Neurocardiogenic syncope (NCS) is a common and sometimes debilitating disorder, with no consistently effective treatment. NCS is due to a combination of bradycardia and vasodilation leading to syncope. Although pacemaker devices have been tried in treating the bradycardic aspect of NCS, no device-based therapy exists to treat the coexistent vasodilation that occurs.

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Background: Pharmacology frequently fails for the treatment of epilepsy. Although surgical techniques are effective, these procedures are highly invasive. We describe feasibility and efficacy of minimally invasive mapping and ablation for the treatment of epilepsy.

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Background: Hemodynamic instability hinders activation and entrainment mapping during ventricular tachycardia ablation. The Impella 2.5 microaxial flow device (MFD; Abiomed Inc.

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Background: Left ventricular assist devices (LVADs) are increasingly used to treat patients with refractory heart failure. Current-generation LVADs have major limitations, including the need for open chest surgery, limiting their widespread use. We hypothesized that the aortoatrial continuity could be used as a unique anatomic vantage point for entirely percutaneous LVAD placement.

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