ECG evaluation by history and tracings -1

Editor's Notes

• #4: The ECG shows: • Regular rhythm at 60/min • Occasional P waves not related to QRS complexes (e.g. lead I) • Left axis • QRS complexes preceded by a sharp 'spike' • Broad QRS complexes (160 ms) • Deep S wave in lead V6 • Inverted T waves in leads I and VL Clinical interpretation The broad QRS complexes show that this is either a supraventricular rhythm with bundle branch block, or a ventricular rhythm. This rhythm is ventricular. The sharp spikes preceding each QRS complex are due to a pacemaker. The P waves that can occasionally be seen indicate that the underlying rhythm, presumably the reason why the pacemaker was inserted, is complete heart block. What to do The SHO has missed the pacemaker, which is usually buried below the left clavicle. There is no particular reason why the pacemaker should be related to the stroke, except that patients with vascular disease in one territory usually have it in others - this man probably has both coronary and cerebrovascular disease. Summary * Permanent pacemaker and underlying compete block.
• #5: The ECG shows: • Regular rhythm at 60/min • Occasional P waves not related to QRS complexes (e.g. lead I) • Left axis • QRS complexes preceded by a sharp 'spike' • Broad QRS complexes (160 ms) • Deep S wave in lead V6 • Inverted T waves in leads I and VL Clinical interpretation The broad QRS complexes show that this is either a supraventricular rhythm with bundle branch block, or a ventricular rhythm. This rhythm is ventricular. The sharp spikes preceding each QRS complex are due to a pacemaker. The P waves that can occasionally be seen indicate that the underlying rhythm, presumably the reason why the pacemaker was inserted, is complete heart block. What to do The SHO has missed the pacemaker, which is usually buried below the left clavicle. There is no particular reason why the pacemaker should be related to the stroke, except that patients with vascular disease in one territory usually have it in others - this man probably has both coronary and cerebrovascular disease. Summary * Permanent pacemaker and underlying compete block.
• #6: The ECG shows: • Broad complex tachycardia at 150/min • No P waves visible • Normal axis • QRS duration about 200 ms • Concordance of QRS complexes (i.e. all point upwards) in the chest leads Clinical interpretation A broad complex tachycardia can be ventricular in origin, or can be due to a supraventricular tachycardia with aberrant conduction (i.e. bundle branch block). Here the very broad complexes and the QRS concordance suggest a ventricular tachycardia. In a patient with a myocardial infarction it is always safe to assume that such a rhythm is ventricular. From the story, one would guess that this patient had a myocardial infarction and then developed ventricular tachycardia, but it is possible that the chest pain was due to the arrhythmia. What to do This patient has haemodynamic compromise - low blood pressure and heart failure - and needs immediate cardioversion. While preparations are being made it would be reasonable to try intravenous lignocaine or amiodarone. Summary Ventricular tachycardia.
• #7: The ECG shows: • Broad complex tachycardia at 150/min • No P waves visible • Normal axis • QRS duration about 200 ms • Concordance of QRS complexes (i.e. all point upwards) in the chest leads Clinical interpretation A broad complex tachycardia can be ventricular in origin, or can be due to a supraventricular tachycardia with aberrant conduction (i.e. bundle branch block). Here the very broad complexes and the QRS concordance suggest a ventricular tachycardia. In a patient with a myocardial infarction it is always safe to assume that such a rhythm is ventricular. From the story, one would guess that this patient had a myocardial infarction and then developed ventricular tachycardia, but it is possible that the chest pain was due to the arrhythmia. What to do This patient has haemodynamic compromise - low blood pressure and heart failure - and needs immediate cardioversion. While preparations are being made it would be reasonable to try intravenous lignocaine or amiodarone. Summary Ventricular tachycardia.
• #8: The ECG shows: • Sinus rhythm • Normal axis • Normal QRS complexes Inverted T waves in leads III, VF; biphasic T waves in lead V4 and flattened T waves in leads v5-v6 Clinical interpretation These T wave changes, particularly those in the inferior leads, could well be caused by ischaemia. The flattened T waves in the lateral leads can only be described as 'non-specific'. What to do When confronted with an ECG showing this sort of 'non-specific' abnormality, action depends primarily on the clinical diagnosis. If the patient is asymptomatic it is fair to report the ECG as showing 'non-specific changes'; if the patient has symptoms at all - as in this case - it is probably worth proceeding to an exercise test. In this patient, the exercise test was perfectly normal, and his symptoms cleared without any intervention. A repeat ECG, recorded purely out of interest a month later, showed similar changes. Summary *** Non-specific ST segment and T wave changes.
• #9: The ECG shows: • Sinus rhythm • Normal axis • Normal QRS complexes Inverted T waves in leads III, VF; biphasic T waves in lead V4 and flattened T waves in leads v5-v6 Clinical interpretation These T wave changes, particularly those in the inferior leads, could well be caused by ischaemia. The flattened T waves in the lateral leads can only be described as 'non-specific'. What to do When confronted with an ECG showing this sort of 'non-specific' abnormality, action depends primarily on the clinical diagnosis. If the patient is asymptomatic it is fair to report the ECG as showing 'non-specific changes'; if the patient has symptoms at all - as in this case - it is probably worth proceeding to an exercise test. In this patient, the exercise test was perfectly normal, and his symptoms cleared without any intervention. A repeat ECG, recorded purely out of interest a month later, showed similar changes. Summary *** Non-specific ST segment and T wave changes.
• #10: The ECG shows: • Sinus rhythm • Normal axis • Probably normal QRS complexes • Gross elevation of ST segments in anterior and lateral leads • Depressed ST segments in the inferior leads and leads III, VF Clinical interpretation Acute anterolateral myocardial infarction. In the lateral leads I, VL and V4-V6, it is difficult to see where the QRS complexes end and the ST segments begin, but in lead II it is clear that the QRS complex is of normal width. What to do If the patient gives a history suggestive of a myocardial infarction and has this ECG, no further investigations are needed in the acute phase of the illness, and in particular there is no place for a chest X-ray. Routine treatment for a myocardial infarction - pain relief, aspirin and thrombolysis - should be commenced immediately. Summary Acute anterolateral myocardial infarction.
• #11: The ECG shows: • Sinus rhythm • Normal axis • Probably normal QRS complexes • Gross elevation of ST segments in anterior and lateral leads • Depressed ST segments in the inferior leads and leads III, VF Clinical interpretation Acute anterolateral myocardial infarction. In the lateral leads I, VL and V4-V6, it is difficult to see where the QRS complexes end and the ST segments begin, but in lead II it is clear that the QRS complex is of normal width. What to do If the patient gives a history suggestive of a myocardial infarction and has this ECG, no further investigations are needed in the acute phase of the illness, and in particular there is no place for a chest X-ray. Routine treatment for a myocardial infarction - pain relief, aspirin and thrombolysis - should be commenced immediately. Summary Acute anterolateral myocardial infarction.
• #12: The ECG shows: • Narrow complex tachycardia at 200/min • No P waves visible • Normal axis • QRS complexes normal • Some ST segment depression Clinical interpretation This ECG shows supraventricular tachycardia, probably junctional. These rhythms are usually due to a re-entry pathway within, or near to, the atrioventricular node. The ST segment depression could indicate ischaemia, but the ST segments are not horizontally depressed, nor is the depression greater than 2 mm, so it is probably of no significance. What to do The first action is carotid sinus pressure, which may terminate the attack. If this fails it will almost certainly respond to adenosine. As with any tachycardia, electrical cardioversion must be considered if there is haemodynamic compromise. Once sinus rhythm has been restored the patient must be taught the various methods (e.g. the Valsalva manoeuvre) with which she might try to terminate an attack. Prophylactic medication may not be needed if attacks are infrequent, but most patients with this problem should have an electrophysiological study to try to identify a re-entry pathway that can be ablated. Summary Supraventricular (junctional) tachycardia.
• #13: The ECG shows: • Narrow complex tachycardia at 200/min • No P waves visible • Normal axis • QRS complexes normal • Some ST segment depression Clinical interpretation This ECG shows supraventricular tachycardia, probably junctional. These rhythms are usually due to a re-entry pathway within, or near to, the atrioventricular node. The ST segment depression could indicate ischaemia, but the ST segments are not horizontally depressed, nor is the depression greater than 2 mm, so it is probably of no significance. What to do The first action is carotid sinus pressure, which may terminate the attack. If this fails it will almost certainly respond to adenosine. As with any tachycardia, electrical cardioversion must be considered if there is haemodynamic compromise. Once sinus rhythm has been restored the patient must be taught the various methods (e.g. the Valsalva manoeuvre) with which she might try to terminate an attack. Prophylactic medication may not be needed if attacks are infrequent, but most patients with this problem should have an electrophysiological study to try to identify a re-entry pathway that can be ablated. Summary Supraventricular (junctional) tachycardia.
• #14: The ECG shows: • Sinus rhythm, rate 140/min • One ventricular extrasystole • Peaked P waves (best seen in leads II, III, VF) • Normal PR interval • Right axis • Dominant R wave in lead Vl • Deep S wave in lead V6 • Normal ST segments and T waves Clinical interpretation The sinus tachycardia suggests a major problem. The peaked P waves indicate right atrial hypertrophy. The right axis and dominant R wave in lead Va suggest right ventricular hypertrophy. The deep S wave in lead V6, with no Teft ventricular' complexes in the chest leads, indicates 'clockwise rotation' of the heart, with the right ventricle occupying the precordium. These changes suggest lung disease. What to do Since the ECG is entirely 'right sided' one can assume that the problem is due to chronic lung disease or recurrent pulmonary embolism. The story sounds more in keeping with a lung problem. The raised jugular venous pressure is presumably due to cor pulmonale. The sinus tachycardia is worrying, and suggests respiratory failure. Summary ** Sinus tachycardia and one ventricular extrasystole, right atrial and right ventricular hypertrophy, and clockwise rotation suggest chronic lung disease.
• #15: The ECG shows: • Sinus rhythm, rate 140/min • One ventricular extrasystole • Peaked P waves (best seen in leads II, III, VF) • Normal PR interval • Right axis • Dominant R wave in lead Vl • Deep S wave in lead V6 • Normal ST segments and T waves Clinical interpretation The sinus tachycardia suggests a major problem. The peaked P waves indicate right atrial hypertrophy. The right axis and dominant R wave in lead Va suggest right ventricular hypertrophy. The deep S wave in lead V6, with no Teft ventricular' complexes in the chest leads, indicates 'clockwise rotation' of the heart, with the right ventricle occupying the precordium. These changes suggest lung disease. What to do Since the ECG is entirely 'right sided' one can assume that the problem is due to chronic lung disease or recurrent pulmonary embolism. The story sounds more in keeping with a lung problem. The raised jugular venous pressure is presumably due to cor pulmonale. The sinus tachycardia is worrying, and suggests respiratory failure. Summary ** Sinus tachycardia and one ventricular extrasystole, right atrial and right ventricular hypertrophy, and clockwise rotation suggest chronic lung disease.