Reperfusion arrhythmias after chronic regional denervation of the ischaemic myocardium in pigs.
OBJECTIVE
The aim was to assess the effects of chronic regional denervation of the ischaemic myocardium on reperfusion arrhythmias in a model with sparse coronary collateral circulation.


METHODS
Baseline ventricular refractoriness and epicardial activation times were measured together with reperfusion arrhythmias after 15 min (I-15') or 30 min (I-30') of left anterior descending coronary artery occlusion in 38 barbiturate anaesthetised open chest pigs. Twenty pigs (11 in I-15' and nine in I-30') had a chronic (two week) denervation of the left anteroseptal region, whereas 18 pigs (10 in I-15' and eight in I-30') were sham operated (non-denervated) controls. Denervation was induced by pericoronary application of phenol and verified by absence of adrenergic histofluorescence.


RESULTS
As compared with controls, denervated pigs showed: (1) longer activation times: 20.3 (SD 5.2) ms v 16.5 (4.6) ms, p < 0.001; (2) slightly longer refractory periods: 348(28) ms v 334(27) ms; (3) a tendency to lower postreperfusion ectopic activity: ectopic beats divided by time free of ventricular tachycardia: 0.13(0.19) v 0.34(0.40) in I-15', and 0.21(0.24) v 0.39(0.44) in I-30'; (4) slower ventricular tachycardia in I-30': 140(29) beats.min-1 v 185(29) beats.min-1, p < 0.009; and (5) comparable incidence of postreperfusion ventricular fibrillation: 4/11 pigs v 2/10 in I-15', and 5/9 v 4/8 in I-30'.


CONCLUSIONS
Selective chronic denervation of the ischaemic myocardium was unable to protect against malignant reperfusion arrhythmias in hearts with human-like coronary collaterals. This was confirmed at two ischaemic periods known to produce progressive catecholamine accumulation and increased adrenoceptor density in the ischaemic myocardium.
Cinca
J
J
Laboratorio de Cardiología Experimental, Hospital General Universitari Vall d'Hebrón, Barcelona, Spain.
Worner
F
F
Carreño
A
A
Bardají
A
A
Salas-Caudevilla
A
A
Soler-Soler
J
J
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D002395:Catecholamines / Q000032:analysis; D004195:Disease Models, Animal; D004562:Electrocardiography; D005455:Fluorescent Antibody Technique; D017202:Myocardial Ischemia / Q000150:complications* / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000150:complications* / Q000378:metabolism; D009206:Myocardium / Q000737:chemistry; D013552:Swine; D013562:Sympathectomy
D002395:Catecholamines