Current Medical Research and Opinion (1996), 13, No. 6, 325
The actions of talinolol, a B1-selective beta blocker, in cardiac arrhythmia and acute myocardial infarction	I. Aßmann Klinikum Erfurt GmbH, Klinik für Innere Medizin, Abteilung für Kardiologie, Psf. 595, 99012 Erfurt, Germany Received: 15th November 1995

INDEX

Summary

Electrophysiological findings

The majority of patients suffering from sick sinus syndrome, however, present a significant prolongation by approximately 80–260 ms, while the SNRT is extended, in some drastically, by talinolol³ (Table I; Figure 1). In addition, the global maximum AV conduction is, in some patients, significantly decreased. The AH interval is slightly prolonged in all trial groups (Figure 2). In patients with known AV lengthening, conduction in the AV node and the effective refractory period (ERP) are prolonged by talinolol as well,^{2, 24} although no higher-degree AV blockades were observed. A comparison with the effects brought about by 5 mg propranolol i.v. reveals a similar behaviour of the parameters mentioned, with the prolongation of SNRT under propranolol being, in some patients, obviously even more pronounced.^{24, 35}

Under the influence of talinolol, patients with sinus tachycardias show a significant decrease in heart rate and AV conduction time, and a prolongation of the refractory periods in the atrium and in the AV node. The SNRT is not influenced to a significant degree.³ Neither in patients nor in healthy subjects is the intraventricular conduction (HV interval, QRS duration) significantly altered by talinolol. In electrophysiological investigations after intravenous application, talinolol thus displays effects which have been proven to occur also with other beta blockers. They are slightly less pronounced as compared with intravenous propranolol, especially with respect to an influence on AV conduction.

Fig. 1.– Maximal sinus node recovery time (SNRTmax) in patients with sick sinus syndrome (SSS) before and after administration of talinolol (20 mg i.v.).

Fig. 2.–AH time during atrial pacing in patients with sick sinus syndrome before after after administration of talinolol (20 mg i.v.).

Therapeutic effects on tachyarrhythmias during acute and long-term administration

Owing to its sinus node depression, talinolol is used preferably in patients with sinus tachyarrhythmias related to CHD, but also in the treatment of the hyperkinetic heart syndrome. The decrease in heart rate amounts in all investigations to approximately 15–20%. During tachycardiac atrial fibrillation or flutter, the ventricular rate is reduced on average by 15–25 b.p.m.^{12, 26} A conversion to sinus rhythm was observed to occur in 42% of the patients (given the drug (100–150 mg/day) in addition to quinidine and digitoxin) within 1–6 days, on average after 1.73 days.²⁸ The attack rate in supraventricular tachycardias and paroxysmal

atrial flutter is lowered in the majority of patients, while an interruption of supraventricular tachycardias can be brought about only in rare cases (Table II). Talinolol also exerts a significant positive influence on supraventricular and ventricular extrasystoles (SVES and VES), particularly in coronary heart disease when exercise-induced (cf. Figures 3a and b) or related to an increased activity of the sympathetic nervous system. The number and severity of ectopic beats in long-term ECGs was reduced to the same extent as under metoprolol, and was approximately 50% for VES and some 60% for SVES. There were no significant differences between the groups41 (Table III). In a double-blind trial involving a four-week application of 300 mg talinolol daily, Korkusko et al.20 found a significant reduction in SVES and VES, as compared with propranolol 100 mg/day, in patients with coronary heart disease versus placebo. A reduction of > 75% was considered to be a success, 31–74% a minor success and <30% a failure. In the majority of patients, both substances had positive effects, while supraventricular extrasystoles also reacted somewhat more readily in this trial (Table IV). The combination with other antiarrhythmics given in the event of tachyarrhythmias not responding to treatment also had positive effects in a large number of patients, who reported good tolerability and no undesired side effects9 (Table V).

Fig. 3(a)

Fig.3 (b)

Fig. 3(a) and 3(b).–ECG during exercise before (a) and after (b) 20 mg talinolol i.v. in a 56-year-old patient with coronary artery disease.

Table IV.–Influence of talinolol (300 mg/d) p.o. or propranolol (100 mg/d) on ventricular (VES) and supraventricular (SVES) extrasystoles20

	Talinolol	n = 20	vs	placebo	Propranolol	n = 15	vs	placebo
Reduction of arrhythmias	SVES	(%)	VES	(%)	SVES	(%)	VES	(%)
1. O 75%	15	(75)	12	(60)	7	(46.7)	5	(33.3)
2. 30–75%	3	(15)	4	(20)	6	(40)	6	(40)
3. <30%	2	(10)	4	(20)	2	(13)	4	(27)

Table V.–Combination therapy with talinolol on tachyarrhythmias9

	Number of patients	Number of combinations	2	3	4	Very good	Good	No effect

VES/VT151713223122 ST33300120 PSVT68530143 SVES11100010AF88233044

Key

VES = ventricular extrasystoles; VT = ventricular tachycardia; ST = sinus tachycardia; PSVT = parox. supraventricular tachycardia; SVES = supraventricular extrasystoles; AF = atrial fibrillation

Even a higher-degree cardiac failure (NYHA II–III, partly even III–IV) in patients with tachyarrhythmias represents no contra-indication for talinolol. Even when administered parenterally, a deterioration of signs indicating heart failure was observed in only one case, while all other patients showed very good or good effects on arryhthmias, but no negative influence on the clinical symptoms of cardiac failure27 (Table VI).

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