AN ELECTROCARDIOGRAPHIC CRITERION FOR DIAGNOSIS OF PATENT FORAMEN OVALE ASSOCIATED WITH ISCHEMIC STROKE

Background and Purpose-An M-shaped bifid notch on the ascending branch , or on the zenith, of the R wave in inferior ECG leads (II, III, aVF) , so called ''crochetage,'' is an indicator of ostium secundum atrial septal defects. The pathophysiology underlying this finding remains un known. A crochetage pattern has not been previously reported in patien ts with patent foramen ovale (PFO); however, the location of this defe ct and the secundum atrial septum are similar. The purpose of this stu dy was to determine the prevalence of crochetage in cryptogenic stroke patients with or without PFO. Methods-A conservative selection scheme was used to identify patients likely to have had PFO-associated strok es tie, cryptogenic) and to exclude any structural, functional, or vas cular heart disease responsible for ECG changes. All patients had a st andard 12-lead EGG. The prevalence of crochetage in each group was det ermined. Results-Sixty consecutive patients were studied (28 with echo -documented PFO and 32 echo-negative control subjects). The crochetage pattern was present in at least 1 inferior limb lead in 10 of 28 PFO patients (36%) and 3 of 32 control subjects (9%) (P<0.05). The sensiti vity and specificity of the crochetage pattern for diagnosis of PFO in cryptogenic stroke cases were 36% and 91%, respectively; positive pre dictive value was 77%. Conclusions-The finding of an ECG crochetage pa ttern may help to identify stroke patients with PFO, may help to strea mline their diagnostic workup, and may warrant future studies to deter mine its value in stratifying stroke risk in patients with PFO.