LETTERS

maneuver and that when the smus recovery time IS measured after the admmistration of atropme m these patients the recovery period is considerably lengthened (Ref 3 of Seipel and Breithardt) This effect is probably related to enhancement of retrograde penetration of the electrical stirnub into the SInoatrial node, resulting m more profound depression of sinoatrial recovery It appears that atropme reverses smoatrial entrance block by blocking the vagal effect that depresses smoatrial conduction The data of Seipel and Brelthardt suggest a similar effect after the mtravenous admnnstration of disopyramlde From the therapeutic standpoint, if the antiarrhythmic agent is useful m suppressmg the tachyarrhythmia that may cause overdrive suppression of the smoatria1 node it still may not cause post-tachycardia syncope If the data presented can be extrapolated to other patients with sick sinus syndrome or smoatrial syncope, it follows that the admmlstratmn of disopyramlde under control conditions may uncover the “brady” phase of this syndrome after overdrive suppression in persons with normal smus recovery times at rest This may be a useful diagnostic test However, m our experience, the syndrome of tachycardia-bradycardia accompamed by syncope is best treated with a combmation of ventricular pacing and drug therapy Benjamin

Befeler,

Cardiovascular Unlverslty Veterans

of Mlaml MedIcal Admmlstratlon

School and

Hospital

Reference Slrauss HC, Saroff AL, Bigger JT Jr Premature atrlal stlmulat~on as a key to the “nderstandlng of slnoatrlal conduction I” man Present&on of data and crdlcal review of the Merature Cwculabon 47 86-93. 1973

INTERNAL

MAMMARY-PULMONARY

Bruce H Brundage, Denver,

MD, FACC, LTC, MC

Colorado

References Cohen EM, Loew DE, Messer JV Internal mammary arter~ovenous malformatKan wth communvxdon to pulmonarv vessels Am J Cardlol 35 103-106. 1975 Brundage BH, Gomez iC, Chelilln MD, et al Systemic artery to pulmonary vessel flstulas Chest 62 19-23, 1972 Burchell HB, Clagelt T The cl~ntcal syndrome assocaated wth pulmonary arterwenous ftstulas lncludlng a case report of a surgvzal cure Am Heart J 34 151-162. 1947 Away A, Csakany C, Tommy E Systemic arterial pulmonary arterial commun~cat,on I” a case of Fallots pentalogy Acta RadIoI [Dlagn] (Stockh) 3 151-155, 1965 lntontl F, Marchegianl C Congenltal coronary and systemic-pulmonary ftstulas slmulatlng a patent wth ductus arter~osus Ann ltal Char 41 1091-l 101. 1965 Lurus AG, Cowen RL, Eckert JF Systemic pulmonary arter~~~en~~~ flstula foltwang closed tube thoracotomy Radiology 92 1296-1296. 1969 Scott BF, Hair TE Jr Cysbc dwase of the lung with acquwed systemic pulmonary shunt DIS Chest 38 459-461. 1960 Cullbed I, Bjork L, Bjork VO Congendal perlcardnl arter~ovenous flstula Am Heart J64111-116 1962

MD, FACC

Laboratory

Miami, Florida

1

cal pulmonary or systemic artermvenous fistulas, we believe systemic artery to pulmonary vessel fistula would be a clearer term We found 28 other reported cases of systemic artery to pulmonary vessel commumcation and thmk that the case of Cohen et al would better be associated with these malformations than with mternal mammary artery to vein fistulas

ARTERIOVENOUS

MALFORMATION

The recent article by Cohen et al l on mternal mammary artery to pulmonary vessel commumcations was of great interest My group reported two similar cases2 and 11 addltional cases, ?-s 6 of which were not mentioned bv Cohen et al They described their reported anomaly as an “mternal mammary arteriovenous malformation with commumcation to pulmonary vessels ” From their anglograms and diagrams, we cannot discern mvolvement of the internal mammary vein m the malformation The only egress of contrast medium from the malformation seems to be by way of arteries and the vessel drannng to the left pulmonary vein Because of the possibihty of confusion with typi-

REPLY

We thank Dr Brundage for his additions to our bibhography on internal mammary artery to pulmonary vessel commumcations However, our anglograms did reveal that the prmcipal efferent vessel drammg the vascular malformation was mdistmguishable from the internal mammary vem This vessel can be seen to accompany the artery m our Figure 3 The route of entry from the thoracm vascular malformation mto the pulmonary circulation was vlsualized m serial films as a later fillmg vessel coursmg to the left upper pulmonary lobe We therefore believe that our case represents a systemic arteriovenous fistula involvmg the internal mammary vessels with comcident commumcation to the pulmonary circulation, perhaps as a result of the patient’s prior granulomatous lung disease We agree that the termmology regarding pulmonary arteriovenous fistulas, systemic arteriovenous fistulas and systemic artery to pulmonary vessel fistulas may be confusing, but believe that our case mcorporates features of the latter two entities and that the clearest descriptive term remains that given m our title

June 1976

Edward M Cohen, MD Donald E Loew, MD Joseph V Messer, Palm Desert,

The American Journal of CARDIOLOGY

MD, FACC

Callfornla

Volume 37

1119