You are dispatched to an “unknown medical complaint.” En route to the scene, dispatch advises you that a 66 year old male is complaining of a fall with injury, chest pain, left arm pain, and nausea.
On arrival, the patient is standing in his kitchen. He is pale and extremely diaphoretic. You direct him to a chair so you can obtain a history of the present illness.
The patient states that he “passed out” in the bathroom the night before and twice this morning. The most recent episode was in the kitchen just before the patient’s spouse contacted 9-1-1.
The patient states he has always been healthy except for a “little bit of high blood pressure”, high cholesterol, and “a right bundle branch block which is at least 20 years old.” There is no other history of syncope or falls.
The patient is alert and oriented to person, place, and time, but he admits that he is “foggy” with regard to the syncopal episodes. However, he denies hitting his head and states he has no head or neck pain.
A 2 cm horizontal laceration is noted under the patient’s chin. He doesn’t remember the last time he had a tetanus shot. He is also complaining of posterior rib pain on the right side. The pain is worse with inspiration and palpation but the chest wall is stable. He denies shortness of breath. He denies arm pain. He is not nauseated at the time of EMS evaluation.
Vital signs are assessed.
- HR: 90
- RR: 16
- NIBP: 105/60
- SpO2: 96 on RA
Breath sounds are clear bilaterally
The cardiac monitor is attached.
By this time the patient “feels better.” He is no longer diaphoretic and he thinks he’ll “be okay.”
The patient is adamant that he does not want to be transported to the hospital.
Do you think he needs to go to the hospital?
What do you think is causing his syncope?
How do you explain to the patient the risk he is taking by refusing care?
The 12-lead ECG shows bifascicular block (right bundle branch block and left anterior fascicular block). In addition there is a slight first degree AV block. Some cardiologists refer to first degree AV block as “PR prolongation” because it is not a true block (the impulse reaches the ventricles in a 1:1 ratio).
Others might point to bifascicular block with first degree AV block and say that this ECG shows “trifascicular block” but that is controversial. The guidelines require alternating right and left bundle branch block, or bifascicular block with alternating left anterior and posterior fascicular block, or documented second or third degree block, in addition to bifascicular block in order to call it true “trifascicular block”.
Regardless, the presence of bifascicular block in a syncope patient is concerning because it suggests that conduction through the last remaining fascicle is precarious. There’s a good chance this patient is experiencing intermittent third degree AV block, although he could also be experiencing runs of ventricular tachycardia. Without documenting the arrhythmia we can’t say for certain but this history of present illness suggests cardiac syncope.
Here is an excerpt from Epstein A, DiMarco J, Ellenbogen K et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. Journal of the American College of Cardiology. 2008;51(21):e1-e62. doi:10.1016/j.jacc.2008.02.032. (PDF)
2.1.3. Chronic Bifascicular Block
“Syncope is common in patients with bifascicular block. Although syncope may be recurrent, it is not associated with an increased incidence of sudden death. Even though pacing relieves the neurological symptoms, it does not reduce the occurrence of sudden death. An electrophysiological study may be helpful to evaluate and direct the treatment of inducible ventricular arrhythmias that are common in patients with bifascicular block. There is convincing evidence that in the presence of permanent or transient third-degree AV block, syncope is associated with an increased incidence of sudden death regardless of the results of the electrophysiological study. Finally, if the cause of syncope in the presence of bifascicular block cannot be determined with certainty, or if treatments used (such as drugs) may exacerbate AV block, prophylactic permanent pacing is indicated, especially if syncope may have been due to transient third degree AV block.”
1. Permanent pacemaker implantation is reasonable for syncope not demonstrated to be due to AV block when other likely causes have been excluded, specifically ventricular tachycardia (VT). (Level of Evidence: B)”
Bifascicular block is an ECG finding that should be included along with hypertrophic cardiomyopathy (HCM), the Brugada pattern, long/short QT interval, the Wolff-Parkinson-White pattern (WPW), and arrhythmogenic right ventricular dysplasia (ARVD), and of course ischemia or arrhythmia, in the evaluation of the syncope patient.
There’s no shame in transmitting an ECG to the hospital for a physician over-read. I’ve done it several times for borderline ECGs, especially for syncope, and particularly when there is no prodrome and the history does not suggest dehydration or vasovagal syncope.
In this case the patient understood the risk of refusing care and refused transport to the hospital. He was encouraged to follow up with his physician and contact 9-1-1 again if he changed his mind.