EXTRASYSTOLES

Extrasystoles occurring in young people with no other cardiovascular abnormality do not require treatment, and as a rule are resistant to medication. The patient should be reassured as to their innocent nature and should not per¬mit the arrhythmia to interfere with his normal activities. Cases of persistent extrasystolic irregularity occur in healthy young athletes and many people who have had extrasystoles throughout life survive to old age.
Patients who are greatly troubled by sensations due to extrasystoles may require a sedative, such as 30 to 60 mgof phenobarbitone. There is evidence that barbiturates in some cases may diminish the frequency of extra" systoles.
Extrasystoles developing de novo in a patient demand careful overhaul toi exclude organic cardiac disease, and a search must be made for possible exciting factors such as heavy meals before retiring to bed, flatulence, tobacco or caffeine in excess, septic foci in teeth or elsewhere, and digitalis overdosage. During some days following a myocardial infarction, extrasystoles may be conspicuous and should be regarded as danger signals. Since they may herald a paroxysm of ventricular tachycardia or a fatal ventricular fibrillation their suppression advisable using quinidine, 0-2 to 0-3 g. (3 to 5 gr.) four-hourly; or procaineamide may be used, 0-25 g. four-hourly.
Multiple extrastoles may cause a pulse irregularity so great as to simulate atrial fibrillation. If they are not attributable to digitalis overdosage this drug is useful in treatment. To be effective, digitalization must be thorough, and its administration does not differ from that in cases of atrial fibrillation. The continued administration of digitalis to a patient already intoxicated by it is, of course, highly dangerous, and may lead to ventricular tachycardia and sudden death; hence the need to be certain that digitalis is not responsible before starting treatment. Extrasystoles appearing in a patient receiving digitalis should be presumed to be due to the drug till proved of other origin by their persistence for a fortnight after cessation of digitalis therapy. Quinidine sul¬phate, given as above, is useful in some cases, and is a safer drug than digitalis ,n the first week after a myocardial infarction. Coupled rhythm, or pulsus Ugeminus, is usually due to overdosage with digitalis, and this explanation should be assumed correct until it has been dis¬proved. Keeping this rule will avoid accidents from digitalis overdosage.
SINO-ATRIAL BLOCK, NODAL RHYTHM, ETC.
There is no indication for medication in cases of sino-atrial block, or in the other rare disorders such as interference-dissociation. Some of these are prone to occur under digitalis therapy, and should such a cause be suspected the drug should be temporarily withheld.