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When Palpitations Worsen
ECG IMAGE OF THE MONTH Julia H. Indik, MD, PhD, Section Editor
When Palpitations Worsen Julia H. Indik, MD, PhD Sarver Heart Center, University of Arizona, Tucson.
A 39-year-old woman was visiting with friends in Texas. She awoke in the night with difficulty breathing and chest pressure, in addition to being aware that her heart was racing. She had noted similar occurrences twice in the previous year, none as severe as the current episode. Her past medical history included a history of depression that was resolved. She did note a prior history of syncope at the age of 10, which at the time was attributed to dehydration. Due to her severe symptoms, she presented to a local Emergency Room, and an ECG was obtained (Figure 1). Her initial blood pressure was recorded in triage as 136/37, but over the course of the following hour she required a fluid bolus of 300 cc of normal saline. Shortly afterwards she became unarousable, and the ECG in Figure 2 was recorded. The patient was then administered lidocaine 100mg IV followed by synchronized shocks at 20J, 50J and finally 100J to achieve sinus rhythm (Figure 3). Funding: None. Conflict of Interest: None. Authorship: Dr. Indik wrote this manuscript and is responsible for the content. Requests for reprints should be addressed to Julia H. Indik, MD, PhD, Sarver Heart Center, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724. E-mail address: [email protected]
ASSESSMENT Figure 1 shows an irregularly irregular wide complex rhythm. The overall rate is about 250 bpm, but there are some QRS complexes that come as close as 160 ms. There is one beat (noted with an asterisk) with a narrow QRS complex. Figure 2 shows her ECG obtained just before she was shocked and shows ventricular fibrillation. Her ECG in sinus rhythm (Figure 3) demonstrates the presence of a delta wave.
DIAGNOSIS The patient’s presenting rhythm (Figure 1) is atrial fibrillation with rapid conduction over an accessory bypass tract. This patient has Wolff-Parkinson-White (WPW) Syndrome. Conduction proceeds over both the bypass tract the AV node, but predominantly over the bypass tract as nearly all QRS complexes are bizarrely wide, with the exception of the QRS complex that is narrow (*) which represents predominant conduction over the AV node. This ECG should not be confused with ventricular tachycardia, which would not have been as irregular as in this case, nor should this ECG be confused with aberrant His-Purkinje conduction, such as right bundle branch block. In sinus rhythm (Figure
Figure 1 Presenting ECG. There is an irregularly irregular, wide complex rhythm at about 250 bpm. One QRS complex is narrow (*); what does this imply?
0002-9343/$ -see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.amjmed.2010.01.012
518
The American Journal of Medicine, Vol 123, No 6, June 2010
Figure 2
ECG obtained when the patient became unarousable. She was subsequently shocked. What is this rhythm?
3) there is a positive wave in lead V1 indicating a left sided bypass tract. Patients with Wolff-Parkinson-White may develop atrial fibrillation which can be life threatening if the accessory bypass tract has rapid antegrade conduction, as in this patient. The shortest interval between consecutive QRS complexes in figure 1 is about 160ms. It is generally held that the presence of very short R-R intervals in atrial fibrillation, particularly less than 220 ms, indicates a higher risk for sudden cardiac death due to degeneration
Figure 3
to ventricular fibrillation.1 The incidence of sudden cardiac death in WPW has been estimated at 0.15% per year2,3 and risk is increased in patients with multiple bypass tracts.4,5 Patients with symptoms should be referred for catheter ablation, but the management of truly asymptomatic invidividuals is controversial.1 Ventricular fibrillation can occur spontaneously, as in this patient, or be precipitated by the administration of medications such as verapamil, in which vasodilation from the drug may increase sympathetic tone, which in turn can increase
ECG following a 100J shock showing the restoration of sinus rhythm. What is this patient’s diagnosis?
Indik
When Palpitations Worsen
conduction over the bypass tract.6 The treatment for preexcited atrial fibrillation with rapid conduction should be focused to restoring sinus rhythm as soon as possible. Patients who appear hemodynamically stable can be treated with antiarrhythmic medications such as ibutilide or procaineamide, but since the hemodynamic status can deteriorate quickly cardioversion is often preferred to restore sinus rhythm.
MANAGEMENT An electrophysiology study confirmed the presence of a lateral left sided bypass tract, mapped to a 3:00 position on the mitral annulus and which was successfully ablated. The patient has remained free of symptoms and with a normal QRS complex without delta wave upon followup.
519
References 1. Tischenko A, Fox DJ, Yee R, et al. When should we recommend catheter ablation for patients with the Wolff-Parkinson-White syndrome. Curr Opin Cardiol. 2008;23:32-37. 2. Flensted-Jensen E. Wolff-Parkinson-White syndrome: a long term follow-up of 47 cases. Acta Med Scand. 1969;186:65-74. 3. Munger TM, Packer DL, Hammill SC, et al. A population study of the natural history of Wolff-Parkinson-White syndrome in Olmsted county, Minnesota, 1953-1989. Circulation. 1993;87:866-873. 4. Klein GJ, Bashore TM, Sellers TD, et al. Ventricular fibrillation in the Wolff-Parkinson-White syndrome. N Engl J Med. 1979;301:1080-1085. 5. Pappone C, Manguso F, Santinelli R, et al. Radiofrequency ablation in children with asymptomatic Wolff-Parkinson-White syndrome. N Engl J Med. 2004;351:1197-205. 6. Gulamhusein S, Ko P, Carruthers SG, Klein GJ. Acceleration of the ventricular response during atrial fibrillation in the Wolff-ParkinsonWhite syndrome after verapamil. Circulation. 1982;65:348-354.
When Palpitations Worsen Julia H. Indik, MD, PhD Sarver Heart Center, University of Arizona, Tucson.
A 39-year-old woman was visiting with friends in Texas. She awoke in the night with difficulty breathing and chest pressure, in addition to being aware that her heart was racing. She had noted similar occurrences twice in the previous year, none as severe as the current episode. Her past medical history included a history of depression that was resolved. She did note a prior history of syncope at the age of 10, which at the time was attributed to dehydration. Due to her severe symptoms, she presented to a local Emergency Room, and an ECG was obtained (Figure 1). Her initial blood pressure was recorded in triage as 136/37, but over the course of the following hour she required a fluid bolus of 300 cc of normal saline. Shortly afterwards she became unarousable, and the ECG in Figure 2 was recorded. The patient was then administered lidocaine 100mg IV followed by synchronized shocks at 20J, 50J and finally 100J to achieve sinus rhythm (Figure 3). Funding: None. Conflict of Interest: None. Authorship: Dr. Indik wrote this manuscript and is responsible for the content. Requests for reprints should be addressed to Julia H. Indik, MD, PhD, Sarver Heart Center, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724. E-mail address: [email protected]
ASSESSMENT Figure 1 shows an irregularly irregular wide complex rhythm. The overall rate is about 250 bpm, but there are some QRS complexes that come as close as 160 ms. There is one beat (noted with an asterisk) with a narrow QRS complex. Figure 2 shows her ECG obtained just before she was shocked and shows ventricular fibrillation. Her ECG in sinus rhythm (Figure 3) demonstrates the presence of a delta wave.
DIAGNOSIS The patient’s presenting rhythm (Figure 1) is atrial fibrillation with rapid conduction over an accessory bypass tract. This patient has Wolff-Parkinson-White (WPW) Syndrome. Conduction proceeds over both the bypass tract the AV node, but predominantly over the bypass tract as nearly all QRS complexes are bizarrely wide, with the exception of the QRS complex that is narrow (*) which represents predominant conduction over the AV node. This ECG should not be confused with ventricular tachycardia, which would not have been as irregular as in this case, nor should this ECG be confused with aberrant His-Purkinje conduction, such as right bundle branch block. In sinus rhythm (Figure
Figure 1 Presenting ECG. There is an irregularly irregular, wide complex rhythm at about 250 bpm. One QRS complex is narrow (*); what does this imply?
0002-9343/$ -see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.amjmed.2010.01.012
518
The American Journal of Medicine, Vol 123, No 6, June 2010
Figure 2
ECG obtained when the patient became unarousable. She was subsequently shocked. What is this rhythm?
3) there is a positive wave in lead V1 indicating a left sided bypass tract. Patients with Wolff-Parkinson-White may develop atrial fibrillation which can be life threatening if the accessory bypass tract has rapid antegrade conduction, as in this patient. The shortest interval between consecutive QRS complexes in figure 1 is about 160ms. It is generally held that the presence of very short R-R intervals in atrial fibrillation, particularly less than 220 ms, indicates a higher risk for sudden cardiac death due to degeneration
Figure 3
to ventricular fibrillation.1 The incidence of sudden cardiac death in WPW has been estimated at 0.15% per year2,3 and risk is increased in patients with multiple bypass tracts.4,5 Patients with symptoms should be referred for catheter ablation, but the management of truly asymptomatic invidividuals is controversial.1 Ventricular fibrillation can occur spontaneously, as in this patient, or be precipitated by the administration of medications such as verapamil, in which vasodilation from the drug may increase sympathetic tone, which in turn can increase
ECG following a 100J shock showing the restoration of sinus rhythm. What is this patient’s diagnosis?
Indik
When Palpitations Worsen
conduction over the bypass tract.6 The treatment for preexcited atrial fibrillation with rapid conduction should be focused to restoring sinus rhythm as soon as possible. Patients who appear hemodynamically stable can be treated with antiarrhythmic medications such as ibutilide or procaineamide, but since the hemodynamic status can deteriorate quickly cardioversion is often preferred to restore sinus rhythm.
MANAGEMENT An electrophysiology study confirmed the presence of a lateral left sided bypass tract, mapped to a 3:00 position on the mitral annulus and which was successfully ablated. The patient has remained free of symptoms and with a normal QRS complex without delta wave upon followup.
519
References 1. Tischenko A, Fox DJ, Yee R, et al. When should we recommend catheter ablation for patients with the Wolff-Parkinson-White syndrome. Curr Opin Cardiol. 2008;23:32-37. 2. Flensted-Jensen E. Wolff-Parkinson-White syndrome: a long term follow-up of 47 cases. Acta Med Scand. 1969;186:65-74. 3. Munger TM, Packer DL, Hammill SC, et al. A population study of the natural history of Wolff-Parkinson-White syndrome in Olmsted county, Minnesota, 1953-1989. Circulation. 1993;87:866-873. 4. Klein GJ, Bashore TM, Sellers TD, et al. Ventricular fibrillation in the Wolff-Parkinson-White syndrome. N Engl J Med. 1979;301:1080-1085. 5. Pappone C, Manguso F, Santinelli R, et al. Radiofrequency ablation in children with asymptomatic Wolff-Parkinson-White syndrome. N Engl J Med. 2004;351:1197-205. 6. Gulamhusein S, Ko P, Carruthers SG, Klein GJ. Acceleration of the ventricular response during atrial fibrillation in the Wolff-ParkinsonWhite syndrome after verapamil. Circulation. 1982;65:348-354.