Roberto Pirola Corso avanzato di elettrocardiografia ECG 28° CORSO PER INFERMIERI IN CARDIOLOGIA - DIPARTIMENTO CARDIOLOGICO «A. DE GASPERIS» CORSO ECG AVANZATO

CORSO AVANZATO DI ELETTROCARDIOGRAFIA Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA It is possible to distinguish lead reversal and dextrocardia by watching the precordial leads. Dextrocardia will not show any R wave progression in leads V1-V6, whereas lead reversal will. Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA Dextrocardia and Dextroposition Definition Dextrocardia: Electrical axis of the heart is directed inferiorly and to the right. There are several variants of dextrocardia: 1. Dextrocardia and situs inversus (mirror image dextrocardia): in addition to the heart, internal organs (of abdomen) are also positioned on the opposite side. 2. Dextrocardia and situs solitus: Only heart is on the opposite side; internal organs are not affected. Dextroposition: The anatomically corrected heart is displaced to the right hemithorax. Causes: deformities of chest wall, deformities of diaphragm, postpneumonectomy, hypoplastic right lung, eventration of diaphragm, left hemidiaphragmatic paralysis, pneumomediastinum. Mesocardia: The heart is placed in the midline of thorax. Apex of the heart is either in the midline or directed towards right. Heterotaxy: (abnormal placement) Thoracic and abdominal organs are are placed abnormally. There is no right-left relationship between the organs: neither situs solitus, nor situs inversus. ECG criteria In mirror-image dextrocardia, the axes of P wave, QRS complex and T wave are directed to the right and inferior. This results in positive P waves in leads III and aVF and negative P waves in leads I and aVL. Not only the P wave, but QRS complex and T waves are also negative in lead I. In dextrocardia, normal progression of the R wave is not observed in chest leads. Differential diagnosis When arm leads are reversed the P wave becomes negative in lead I and positive in lead aVR. In addition to the P wave, QRS complex and T wave are also negative in lead I. However, reversal of arm leads does not affect R progression in chest leads resulting in an increase in R wave amplitude from lead C1 to C5: normal R wave progression. Clinical significance In a patient with dextrocardia, it will be easier to comment on the ECG if the chest electrodes are symmetrically placed on right chest and the arm leads are reversed Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA Figure 1. Dextroposition, mirror-image dextrocardia and congenitally corrected transposition of the great arteries. The above figure is a modified version of a figure that originally appeared in Military Medicine 2007;172:vii-ix (with permission). Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 1a. The ECG above belongs to a 30 years-old woman. Precordial electrodes are placed on left chest (standard placement). There is no R progression in chest leads. Calibration is at 10 mm/mV Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 1b. In order to see the P waves of limb leads more clearly, the ECG was recorded again at a calibration of 20mm/mV. The chest electrodes are still on the left side. The P wave is negative in leads I and II, but positive in leads III and aVF. No R wave progression is seen in the anterior leads. Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 1c. The above ECG belongs to the same patient. This time, chest electrodes are symmetrically placed on right chest and arm leads are reversed purposefully. Now, R wave progression is seen in anterior leads and the P wave is upright (positive) in leads I and II. The ECG is calibrated at 10 mm/mV Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 1d. The electrodes are placed same as in ECG 1c; only the calibration is 20 mm/mV Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 2a. This ECG belongs to a 52 years old man who had undergone stenting of the right coronary artery for the treatment of acute inferior wall myocardial infarction 1 year ago. The ECG above was recorded during a routine control and the patient was asymptomatic. There are Q waves and negative T waves in the inferior leads. Lacking ST elevation and typical chest pain, these ECG findings suggest OLD inferior wall myocardial infarction. The patient also has dextrocardia. Because of dextrocardia, QRS complex and T wave are upright in lead aVR while they are negative in lead I . This finding is not due to arm lead reversal since there is no expected R wave progression in the chest leads. Contrarily, the amplitude of the R wave decreases from C1 to C6. Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 2b. The above ECG belongs to the same patient but was recorded after the electrodes were symmetrically placed on the right chest. The ECG now shows proper R wave progression . Old inferior myocardial infarction and abnormal appearance in lead aVR persists Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 3a. The ECG tracing above belongs to an 11 years-old girl and shows leads I, II and III. She has right lung agenesis (complete absence of right lung) and dextrocardia. Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 3b. Leads aVR, aVL and aVF of her ECG. Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 3c. Leads V1, V2 and V3 of her ECG Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012

CORSO AVANZATO DI ELETTROCARDIOGRAFIA ECG 3d. Leads V4, V5 and V6 of her ECG Gruppo di miglioramento – Ospedale Niguarda Ca’ Granda, Milano – Maggio 2012 RP 5/2012