Electrocardiographic Patterns of Atrial Septal Defects

January 15, 2004, a total of 104 consecutive patients of ASD were studied at Punjab Institute of Cardiology, Lahore. Patients were included in the study after confirmation of Atrial Septal Defe t on transesophageaI echocardiography. Results: The mean age of the study population was 26.28:1:11.40 years. Among these 56(53.8%) patients were females and 48(46.2%) patients were males. The study population consisted of 94(90.4% ecundum ASD patients followed by Sinus Venosus ASD 8(7.7%) patients and Primum ASD in only 2(1.9%) patients. OnI.· 59(56.7%) patients had crochetage pattern in any of the leads while it was absent in 45(43.3%) patients p=0.470. Incomplete RBBB was present in 92(88.4%) patients. It was observed in 2(1.9%) patients in ASD Prirnum, 82(78.8%) patient in ASD Secundum and 8(7.7%) patients in ASD Sinus enosus type. P=0.483. Conclusion: Although we did no 0 erve a statistically significant association between crochetage pattern or incomplete RBBB and 'ASD but the presence 0-any of these two considerably increases the specificity of the ECG for the diagnosis of ASD. veywords

study.After confirmation by echo .all patients had a tandard 12 lead ECG with sensitivity of 10 rrunlmV at 25 mrn ec paper speed.Analyses of the tracings were performed in each case by two independent observers.Right bundle branch block on the ECG was defined as complete when QRS duration \ as 2':1.20mSee in adults with a r or R aspect in right precordial leads (VI or V2) and irh a deep S wave in lateral leads (V5, V6 and I, aVI... RBBB was defined as incomplete when QRS d on was less than 120 m See with a r or R' in lead V I or -_.~Crochetage pattern was defined as a rapid up and do "II mouon or the R wave tracing on its ascendant bran h or near its zenith with an -shaped or a bifid panern in the most typical form and always involving the initial 0 m ec of the QRS complex.ECG was carried out to define patients for the absence or presence of a "Crochetage" aspect of R wave in one or more of limb leads II III or aVF.(Figure 1 shows a classical ECG of crochetage pattren).A proforma was filled for each patient in which age, sex, type of atrial septal defect, crochetage pattern, QR morphology and bundle branch pattern, if any, were noted.In this setting, an incomplete right bundle branch .may often lead towards an echocas iographic e. nation but it is lacking in specificity!"!',

Electrocardiographic Patterns of Atrial Septal Defects
This study was designed to evaluate the electrocardiographic feature of Atrial Septal Defect for an association with crochetage pattern and incomplete RBBB.
Mate'~ial a id.rnethodsFrom October' I5, 200'" till January 15,2004, a total of 104 consecutive patients of ASD were studied at the Punjab Institute of Cardiology Lahore.Patients were included in the study r,fret confirmation of Atrial Septal Defect on transesophageal echocardiography.
ASDs of Primum, Secun~um and Sinus Venosus type were included in this Results A.fterfu\ft\hng the inclusion criteria.\()4 patients of ASD were studied.The mean age of the study population was 26.28± 11.40 years.Among the e -'::'.%) patients were females and 48(46.2%)patien -ere male .The study population consisted of three.
of A Ds: Secundum ASD being observed in the [oriry of the patients 94(90.4%)followed by Sin enosus ASD 8(7.7%) patients and Pnmum ASD in only _( .9"0)patients (Table 1 ) The examination of 12 lead ECG re -ealed that the mean heart rate per minute on ECG . .=18.07 beats.
Pearson Chi square was a lied to study the association between crochetage pa em and ASD types.Only 59(56.7%)patients had croche ge pattern in any of the leads while it was absent in 5(43.3%)patients p=O.470.Table 2 shows the distribution of crochetage in individual leads.Crochetage pattern was present in only one lead i.e., either II or III or aVF in _1 (20.2%) patients with a distribution of 1(1.0%) patien in ASD primum, 19(18.3%)patients in ASD Secundum and 1(1.0%) in Sinus Venosus type ASD.In two leads i.e. either II, III or II, aVF or III, aVF crochetage pattern was observed in 28(27%)patients:with a distribution of 2 (20.2%) patients with ASD Secundum and 4(3.8%) patients having ASD Sinus venosus type,.Crochetage pattern in all three Inferior leads II, III and aVF' \ as observed in 10(9.6%)patients, 1(1.0%) patients had ASD Primum and 9(8.7%) had ASD Secundum.

Discussion
Atrial Septal Defect is common lesion which if undetected may lead to the occurrence of pulmonary hypertension, arrhythmias, RV failure, cerebral abscess and cerebral paradoxical embolism.All these complications warrant an early detection of ASDs with an aim to early treatment, leading to a reduction in morbidity and mortality in patients having this lesion.ECG is a simple bedside tool which can point towards the potential diagnosis of ASD.Presence of incomplete RBBB in ECG has been known as a marker of ASD for at least 40 years 10, the reason for it to occur may be due to selective hypertrophy of basal!ortion of Right entric1e or to stretching of the peripheral conduction fibres 9 • IO .
Another ECG pattern independent of incomplete RBBB in ASD is Crochetage.Crochetage when present in only one lead has a sensitivity 0'[ ,3.1 %, a specificity of92.6% and a positive predictive value of69% for the diagnosis of Ostium Secundum ASD and achieves a specificity of 1 % if present in all three Inferior I~ds 13.
In the current stud.we observed' that crochetage pattern was present in 59 -6.7%) patients; in onf lead it was observed in 21'(20.2%patients .. This is 'consistent with Heller et al 13 who have reported 15% patients to have crochetage in one lead.We observed 10(9.6%)patients having crochetage in three leads while Helier et ai 13 have reported 27.8% patients showing this pattern in three leads.Crochetage pattern in two leads was noted in 28(27%) patients which is similar to Heller er al 13 who ha ve reported 30.3% patients having crochetage in two leads.
Dcporunent of Cardiologv.Punjab lnstinue ofCardiology, Lahore  Correspondence /0 0,.. Muliarntnad Tahir Mohyud Din, Senior Registrar E Mail: dralll/al/i@yaiIoo.colllObjective:This study was designed to evaluate the electrocardiographic features of Atrial Septal Defect to establish an association with crochetage pattern and incomplete RBBB.Materials and methods: ASDs of Primum, Secundum and Sinus Venosus type were included in this study.From October 15, 2003 till January 15, 2004, a total of 104 consecutive patients of ASD were studied at Punjab Institute of Cardiology, Lahore.Patients were included in the study after confirmation of Atrial Septal Defe t on transesophageaI echocardiography.Results: The mean age of the study population pnl nary hypertension, a _ -. thmias, RV failure and ngestive heart failure -':u-'i..[;:::<i:ilU.retransient right to