To analyze pre- and post-operation electrocardiograms (ECGs) features of patients underwent orthotopic heart transplantation (OHT), and provide evidences for identifying and analyzing post OHT ECGs.

Nine hundreds and ninty-eight pre- and post- OHT standard 12-leads ECGs from 110 consecutive patients, who underwent OHT in our hospital from May 2008 to May 2014, were analyzed.

The mean heart rate(HR)was (86.9±16.4) beats per minute before OHT, and (100.0±0.4) beats per minute after OHT. P wave′s amplitude, duration, amplitude multiplied by duration of donor heart in lead Ⅱ were (0.124±0.069)mV, (111.1±17.2)ms, (14.34±9.51)mV·ms before OHT; (0.054±0.037)mV, (86.9±27.0)ms, (5.02±4.03)mV·ms at 1 month after OHT; (0.073±0.049)mV, (93.9±17.5) ms, (7.00±4.81)mV·ms at 6 years after OHT. ECGs rotation occurred in 83.64%(92/110) patients after OHT, and prevalence of clockwise rotation was 76.36%(84/110). Sinus tachycardia was evidenced in 99.09%(109/110) patients after OHT, and incomplete right bundle branch block was present in 60.91%(67/110) patients after OHT. Pseudo complete atrioventricular block mostly occurred at 2 days after OHT. Prevalence of double sinus rhythm was 27.95%(263/941) post OHT, 40% of them occurred between the 1st and the 2nd month post OHT; the atrial rate of recipient hearts was (104.0±10.2) beats per minucte between the 3rd and the 6th month post OHT, and was (95.3±4.2) beats per minucte between the 4th year and the 5th year. P wave′s amplitude, duration, amplitude multiplied by duration of recipient heart in lead Ⅱ were (0.066±0.055) mV, (52.8±34.7) ms, (4.67±4.95) mV·ms at 1 month after OHT, (0.043±0.040)mV, (44.4±40.5) ms , (3.11±3.61) mV·ms between the 1st year and 2nd year after OHT. The absolute value of P-wave(originating from the donor heart) terminal force in chest leads increased in 48.99%(461/941) patients post OHT, the P-wave terminal force of V₁ , V₂ and V₃ were -0.044(-0.066, -0.028), -0.060(-0.087, -0.038), -0.035(-0.056, 0) mm·s. Notched P wave in chest leads was presented in 10.31%(97/941) patients post OHT. PR segment depression in chest leads occurred in 60.24%(100/166) patients between the 3rd month and the 6th month, the incidence of PR segment depression in V₁ , V₂ and V₃ was 21.04%(198/941), 37.41%(352/941) and 28.69%(270/941), respectively.

OHT is related to significantly changed ECGs. The mean HR increased significantly after OHT, then decreased gradually after half a year to one year, but it was still higher than preoperative mean HR after five or six years; the P waves of donor heart were usually inconspicuous or small in first month after OHT, and they became bigger after 2 months, and their duration and amplitude then became relatively steady afterwards. ECGs rotation, especially the clockwise rotation, was common post OHT. A variety of arrhythmias originating from the donor heart including sinus tachycardia and incomplete right bundle branch block could be found. Pseudo complete atrioventricular block could also be found in the early phase after OHT. With the extension of time, the incidence of double sinus rhythm reduced gradually. The atrial rate and P wave of recipient heart presented with a tendency to become lower. The absolute value of P-waves(originating from the donor heart) terminal force in chest leads (mainly V₁, V₂ and V₃) increased, notched P waves in chest leads (mainly V₁, V₂) and PR segments depression in chest leads (mainly V₂, V₃ and V₄) also belong to typical post OHT ECGs features.

Heart transplantation; Electrocardiography; Arrhythmia