Pseudo-infarct patterns in the Wolff-Parkinson-White syndrome: importance of Q wave-T wave vector discordance

Sudden cardiac arrest due to coronary vasospasm in a patient with Wolff-Parkinson-White syndrome during brain surgery: a case report

Background

Wolff-Parkinson-White (WPW) syndrome has the risk of sudden cardiac death. Without appropriate treatment, coronary vasospasm is also a potentially fatal condition due to ischemia-induced ventricular fibrillation. A rare case of cardiac arrest due to coronary vasospasm during general anesthesia in a patient with pre-existing WPW syndrome is presented.

Case presentation

A 55-year-old man was scheduled for brain surgery under general anesthesia. During surgery, the ECG monitor showed ST segment elevation followed by sustained ventricular tachycardia and the patient’s blood pressure was unmeasurable. Since pseudo-VT with WPW syndrome was suspected, pilsicainide was administered. A few weeks later, a spasm provocation test with acetylcholine was performed, which showed complete spastic occlusion of the right coronary artery.

Conclusions

A rare case of cardiac arrest during surgery in a patient with WPW syndrome, possibly caused by coronary vasospasm, was described.

When a Pseudo-Infarct Electrocardiogram (ECG) Pattern in a Posterior Accessory (Wolff-Parkinson-White) Pathway Masks a True Inferior Infarct

BACKGROUND Wolff-Parkinson-White (WPW) pattern is due to a pre-excitation leading to characteristic ECG changes in sinus rhythm as short PR interval, the presence of delta waves, wide QRS complexes, and potentially Q wave-T wave vector discordance (pseudo-infarct pattern). These later changes can mask the underlying ECG depolarizing solely through the His-Purkinje system. Our case highlights how the ECG of a WPW pattern with a pseudo-infarct pattern can in fact mask a true infarct on the underlying ECG without pre-excitation. CASE REPORT A 61-year-old diabetic man with a recent history of supra-ventricular tachycardia (SVT) presented with the ECG characteristic of a Wolff-Parkinson-White pattern i-e short PR interval of 0.10 s (<0.12 s) and the presence of delta waves in sinus rhythm. In addition, there was a wide significant Q wave in the inferior leads meeting the criteria for significant and pathologic Q waves, related to the pre-excitation and known as a pseudo-infarct pattern. The patient underwent successful ablation of his left inferoseptal accessory pathway. The pre-excitation pattern (short PR and delta wave) disappeared after successful ablation revealed a narrower Q wave in inferior leads, likely from unexpected true old inferior infarction, which was later confirmed by 2D echocardiogram and nuclear stress test (fixed inferior defect). CONCLUSIONS The presence of pseudo-infarct pattern due to a WPW does not always preclude the presence of underlying true infarct pattern, especially in the presence of coronary artery disease risk factors.

Infarction or Pseudo-infarction?

An applicant with a history of paroxysmal atrial fibrillation is found to have QS waves in leads III and AVF suggestive of a prior inferior wall myocardial infarction. Using the relationship between Q wave and T wave vectors in the inferior leads, an alternative explanation is explored.

Early Repolarization Pattern Occurring with the Wolff-Parkinson-White Syndrome

A 35-year-old male presented with the combined ECG abnormality of the early repolarization pattern and the Wolff-Parkinson-White syndrome. This has not been previously reported.

A Practical ECG Criterion to Unmask Left Accessory AV Connections in Patients With Subtle Preexcitation

BACKGROUND

Accessory AV-connections capable of antegrade conduction need to be recognized because of the potential for life-threatening arrhythmias. However, the preexcited ECG pattern may be subtle, especially among left-sided AV-connections. We explored whether additional ECG criteria might help identify left-sided AV-connections.

METHODS

We analyzed 156 patients who underwent an electrophysiology study (EPS) and ablation for paroxysmal supraventricular tachycardias (PSVT). Patients were divided into 2 groups: those with left-sided AV-connections (Group 1) and all other PSVT (Group 2). Various ECG parameters were compared before and after ablation in both groups.

RESULTS

The EPS identified left-sided AV-connections among 43 patients (Group 1) and excluded it among 113 (Group 2). Baseline ECG in Group 1 demonstrated obvious preexcitation among 24/43 patients (55.8%), the remaining 19/43 missing obvious preexcitation. R/S ratio > 0.5 in V1 was noted in 38/43 (88.4%) patients in Group 1 before ablation (median 1.00; IQR 0.58-2.20), including 16/19 (84.2%) patients lacking obvious left-sided AVconnections. Conversely, only 10/113 (8.8%) patients in Group 2 had R/S ratios in V1 ≥ 0.5 (0.20; 0.10-0.31), P < 0.0001. After ablation, the R/S ratio decreased significantly in Group 1 (0.29; 0.17-0.45), P < 0.0001. Thus, a combined criterion of classic preexcitation or R/S ratio ≥ 0.5 on ECG identified 40/43 left-sided AV-connections (sensitivity 93.0%). The negative predictive value of this combined criterion was 103/106 (97.2%).

CONCLUSIONS

In symptomatic patients, combining the R/S ratio (≥ 0.5) in lead V1 with the classic preexcitation pattern on ECG markedly improved the sensitivity to diagnose left-sided AV-connections. This ratio may be particularly useful among patients lacking obvious preexcitation.

Hyperacute T-waves: Wolff-Parkinson-White pattern or acute coronary syndrome?

BACKGROUND

Pre-excitation syndromes can elicit electrocardiogram (ECG) abnormalities that are nearly identical to those associated with acute myocardial ischemia. In the presence of atypical symptoms, stable hemodynamics, and unremarkable levels of cardiac enzymes, the decision whether to subject these patients to coronary angiography, or even non-invasive testing, can be difficult.

OBJECTIVE

To understand that pre-excitation syndrome can mimic acute myocardial injury, but should not preclude a complete ischemic work-up.

CASE REPORT

A 53-year-old man with Wolff-Parkinson-White pattern and coronary artery disease risk factors presented with new-onset substernal chest pain. A baseline ECG was significant for hyperacute T waves. After refusing cardiac catheterization, he was admitted to the cardiac care unit for intravenous heparin and eptifibatide. Although his stay was unremarkable and resting echocardiogram showed normal contractility and valve function, treadmill stress testing was negative for ischemic change, but revealed ST-segment depression with maximum stress in the lateral precordial leads. This was thought to be a "false positive" secondary to his conduction abnormality.

CONCLUSION

No reliable algorithm exists for making an ECG diagnosis of myocardial infarction in the presence of a pre-excitation syndrome. Similarly, current non-invasive modalities have limitations in detecting jeopardized myocardium. If acute or hyperacute injury is suspected, the patient should be emergently referred for cardiac catheterization.

ST-segment elevation in non-atherosclerotic coronaries: a brief overview

The most common, clinically significant cause of ST elevation is an angiographically demonstrable occlusive disease due to atherosclerotic changes in coronary artery. Often, a patient presenting with non-specific complaints and ST-segment elevation on the electrocardiogram, is sent for a cardiac catheterization only to see no luminal stenosis on the angiogram. This clinical review is intended to inform emergency medicine physicians and internists about the conditions in which ST-segment elevation is accompanied with no atherosclerotic lesion on coronary angiography. These situations make a diverse array of conditions ranging from anomalous coronaries to anatomically normal coronaries with varied degrees of myocardial injury. These conditions are briefly reviewed in this article.

Wolff-Parkinson-White syndrome mimicking acute anterior myocardial infarction in a young male patient--a case report

A young male with Wolff-Parkinson-White syndrome whose electrocardiographic pattern was suggestive of acute anterior myocardial infarction is described. A 21-year-old male with a history of ventricular fibrillation after being successfully resuscitated was admitted to the coronary care unit. His electrocardiogram showed ST elevation in the precordial leads (V1-V6). This condition was erroneously interpreted as an acute myocardial infarction. At the fourth day, while ST elevations returned to baseline, short PR interval and delta waves were observed on the ECG. Myocardial infarction was excluded by biochemical tests, echocardiography, and coronary angiography. Electrophysiologic study confirmed Wolff-Parkinson-White syndrome with two accessory pathways.

Pseudo myocardial infarction and pseudo ventricular hypertrophy ECG patterns in Wolff-Parkinson-White syndrome

In Wolff-Parkinson-White (WPW) syndrome, the ventricles are pre-excited through an accessory conduction pathway, bundle of Kent, which directly connects atria with ventricles bypassing the atrioventricular node. The altered sequence of ventricular activation secondary to presence of the bundle of Kent may cause pseudo myocardial infarction and pseudo ventricular hypertrophy patterns on electrocardiogram. The morphology of these pseudo electrocardiographic patterns depends on the anatomical location of the bundle of Kent around the circumference of the atrioventricular ring. Electrocardiograms of the WPW syndrome displaying morphology of different pseudo patterns are presented and the mechanisms causing pseudo patterns are reviewed.

Clinical features of Wolff-Parkinson-White syndrome

Wolff-Parkinson-White syndrome is the most common form of ventricular preexcitation. Understanding this syndrome is fundamental for anyone interested in learning about arrhythmias. This review addresses (1) the historic sequence of events that led to the understanding of this syndrome; (2) the pathologic, embryologic, and electrophysiologic properties of accessory pathways; (3) the epidemiology and genetics of this syndrome; (4) the clinical diagnosis of this syndrome, with special emphasis on the arrhythmias that patients with ventricular preexcitation are predisposed to; and (5) the therapy for patients with Wolff-Parkinson-White syndrome.