The evaluation of beta-adrenergic blockade in cardiac arrhythmias is difficult because of the complex nature of the arrhythmias and the varied modes of action of blocking drugs. Studies have confirmed the therapeutic value of the betaadrenergic blocking drug pronethalol (Alderlin) (Vaughan Williams, 1963 ; Stock and Dale, 1963 ; Payne and Senfield, 1964; Wolfson et al., 1966) and its more poten...
