Figure 1.

Adverse effects of monogenic K channel overexpression on contractility. Action potentials (upper panels) and contractions (lower panels) recorded (22°C) in failing canine myocytes infected with AdShK and maintained in primary culture (1). Expression of ShK current shortened action potentials but also markedly blunted contractions (lower right panel). Prolonged action potentials and diminished K currents are characteristic of myocytes isolated from failing canine ventricles (18). This failing phenotype persists in primary culture (1).