Figure 4: Thyrotoxic Tricuspid Regurgitation and/or Mitral Regurgitation.

A: Primary pathophysiology; B: Secondary pathophysiology. APD = action potential duration; CO = cardiac output; DBP = diastolic blood pressure; ERP = effective refractory period; GAGs = glycosaminoglycans; HR = heart rate; LA = left atrium; LV = left ventricle; LVEDV = left ventricular end-diastolic volume; MHC1: myosin heavy chain; MHC2 major histocompatibility complex; MV = mitral valve; PLB = phospholamban; RA = right atrium; RAAS = renin-angiotensin-aldosterone system; RV = right ventricle; RVEDV = right ventricular end-diastolic volume; RyR = ryanodine receptor; SERCA2a = sarcoendoplasmic reticulum calcium ATPase type 2a; SV = stroke volume; SVR = systemic vascular resistance; TH = thyroid hormone; TV = tricuspid valve; VR = venous return; VSM = vascular smooth muscle.