RESUMO
Junctional ectopic tachycardia (JET) and atrial fibrillation (AF) occur in patients recovering from open-heart surgery (OHS). Pharmacologic treatment is used for the control of post-operative atrial arrhythmias (POAA), but is associated with side effects. There is a need for a reversible, modulated solution to rate control. We propose a non-pharmacologic technique that can modulate AV nodal conduction in a selective fashion. Ten mongrel dogs underwent OHS. Stimulation of the anterior right (AR) and inferior right (IR) fat pad (FP) was done using a 7-pole electrode. The IR was more effective in slowing the ventricular rate (VR) to AF (52 +/- 20 vs. 15 +/- 10%, p = 0.003) and JET (12 +/- 7 vs. 0 +/- 0%, p = 0.02). Selective site stimulation within a FP region could augment the effect of stimulation during AF (57 +/- 20% (maximum effect) vs. 0 +/- 0% (minimum effect), p<0.001). FP stimulation at increasing stimulation voltage (SV) demonstrated a voltage-dependent effect (8 +/- 14% (low V) vs. 63 +/- 17 (high V) %, p<0.001). In summary, AV node fat pad stimulation had a selective effect on the AV node by decreasing AV nodal conduction, with little effect on atrial activity.
Assuntos
Tecido Adiposo/fisiopatologia , Fibrilação Atrial/etiologia , Fibrilação Atrial/prevenção & controle , Nó Atrioventricular/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Terapia por Estimulação Elétrica/métodos , Complicações Pós-Operatórias/prevenção & controle , Animais , Estimulação Cardíaca Artificial/métodos , Modelos Animais de Doenças , Cães , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Período Pós-Operatório , Taquicardia Ectópica de Junção/etiologia , Taquicardia Ectópica de Junção/prevenção & controleRESUMO
We present a complex case of a transapical redo mitral valve-in-valve replacement. Repeat mitral valve replacement was indicated for severe symptomatic bioprosthetic stenosis. In addition to the patient's numerous comorbidities that included diabetes, hepatic cirrhosis, ischemic cardiomyopathy, and atrial flutter, he had undergone a previous open mitral valve replacement that was complicated by sternal dehiscence requiring extensive chest wall reconstruction. Transapical approach was performed through left minithoracotomy incision with balloon-expandable valve. Transapical valve-in-valve replacement of a stenotic mitral bioprosthesis is a viable solution in a patient with previous complex chest wall reconstruction and multiple comorbidities.