This 32 year old woman with a past history of congenital heart disease presents with increasing dyspnoea, marked bilateral leg oedema and an episode of palpitaions associated with chest discomfort. She measured her pulse rate before arriving , and thinks it was about 200 beats per minute. The palpitations and chest discomfort have now resolved.
+ Describe the findings in this ECG
The ECG shows marked right axis deviation and tall R waves in all the precordial leads, i.e. positive concordance is present in the V leads. Narrow but deep Q waves are present in Lead III and Lead aVF. There is widespread ST depression, and (probable) T wave inversion in Lead III and Leads V2 and V3 (the changes in the baseline caused by the atrial rhythm make it difficult to assess the T waves).
The rhythm strip and Lead V1 show atrial activity at a rate of about 188 beats per minute with a (predominately) 2:1 ratio of atrial complexes to ventricular complexes. The ventricular rate in the rhythm strip ranges from 88 beats per minute to 115 beats per minute; the ventricular rhythm is not irregularly irregular, as would be the case in atrial fibrillation. The morphology of the atrial activity in the rhythm strip is suggestive of atrial flutter, but the atrial rate is too slow for atrial flutter. We conclude by saying that an atrial tachycardia is present, that there is variable AVN block, and that atrioventricular dissociation is not present. The self measured prehospital pulse rate of 200 beats per minute is consistent with 1:1 AVN conduction.
The axis and the R wave changes are consistent with right ventricular hypertrophy. The ST-T abnormalities are secondary to the right ventricular hypertrophy. The presenceof marked bilateral leg oedema suggests right heart failure.
There have been many published criteria to identifythe ECG changes produced by right ventricular hypertrophy (See Table). The criteria are most accurate in congenital heart disease. There is intermediate accuracy in acquired heart disease and primary pulmonary hypertension in adults. The lowest accuracy occurs in chronic lung disease.
Right ventricular hypertrophy due to congenital heart disease produces two main ECG patterns: volume overload causes incomplete RBBB and right axis deviation, while pressure overload produces tall R waves (as part of R, Rs or Qr complexes) in right precordial leads as well as right axis deviation. If sinus rhythm is present the P waves are often tall and peaked ( so called p congenitale).
Source: Recommendations for the Standardization and Interpretation of the Electrocardiogram. Part V: Electrocardiogram Changes Associated With Cardiac Chamber Hypertrophy. JACC. 2009; 53: 992–1002