Show notes
CardioNerds (Amit Goyal & Daniel Ambinder) join Virginia Commonwealth University (VCU) cardiology fellows (Ajay Pillai, Amar Doshi, and Anna Tomdio) for a delicious skillet breakfast and amazing day in Richmond, VA! They discuss a fascinating case of a patient with Wolff-Parkinson-White (WPW) and hypertrophic cardiomyopathy (HCM). Dr. Keyur Shah provides the E-CPR and program director Dr. Gautham Kalahasty provides a message for applicants. Episode notes were developed by Johns Hopkins internal medicine resident Colin Blumenthal with mentorship from University of Maryland cardiology fellow Karan Desai.
Jump to: Patient summary - Case media - Case teaching - References
Episode graphic by Dr. Carine Hamo
The CardioNerds Cardiology Case Reports series shines light on the hidden curriculum of medical storytelling. We learn together while discussing fascinating cases in this fun, engaging, and educational format. Each episode ends with an “Expert CardioNerd Perspectives & Review” (E-CPR) for a nuanced teaching from a content expert. We truly believe that hearing about a patient is the singular theme that unifies everyone at every level, from the student to the professor emeritus.
We are teaming up with the ACC FIT Section to use the #CNCR episodes to showcase CV education across the country in the era of virtual recruitment. As part of the recruitment series, each episode features fellows from a given program discussing and teaching about an interesting case as well as sharing what makes their hearts flutter about their fellowship training. The case discussion is followed by both an E-CPR segment and a message from the program director.
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Patient Summary
A man in his mid-60s presented to the ED after an episode of unwitnessed syncope while drinking. Patient had suddenly passed out from a seated position with no prodrome or post-ictal state. He had episodes like this in the past, which were thought to be seizures, but otherwise PMHx only notable for alcohol use disorder. He denied any FH of SCD or syncope. In the ED, exam was unremarkable. Labs notable for mild thrombocytopenia, mild hyponatremia with AKI, 2:1 AST/ALT ratio, elevated NT-proBNP, and a very high lactate that rapidly corrected with fluids. EKG was notable for sinus tachycardia, short PR interval, wide QRS, and delta waves consistent with Wolff-Parkinson-White (WPW) pattern. Echo showed preserved LVEF, thickened LV septum (1.6 cm) and posterior wall (1.3 cm) concerning for hypertrophic cardiomyopathy (HCM). No outflow tract gradient was noted at rest or with stress, and the strain pattern demonstrated apical sparing. Evaluation for cardiac amyloid, including plasma cell dyscrasia and PYP scan, was negative. Cardiac MRI confirmed severely thickened LV inferior and inferolateral walls at 1.7 cm with no LVOT obstruction. 25% of the myocardium demonstrated patchy LGE.
Due to concern for WPW syndrome, the patient underwent an EP study. This revealed a malignant septal accessory pathway that was successfully ablated with resolution of the WPW EKG features. Given large LGE burden in setting of HCM, patient underwent placement of primary prevention ICD. Genetic testing for PRKAG2 mutation is pending given comorbid WPW and HCM.
Case Media
AECDBFClick to Enlarge
A. CXR: Slightly increased interstitial markings in the lung bases, an elevated right hemidiaphragm. No acute airspace disease or pulmonary edemaB. ECG: Sinus tachycardia rate 120bpm, PR interval 80ms, QRS 130ms, WPW pattern. Arruda algorithm localizes to posterior septum.C. CMR: Myocardium nulls before blood pool.D. CMR: Delayed gadolinium enhancementE. Follow up ECG: NSR 78, repolarization abnormalities. T wave memory inferior leads.F. CXR status post dual chamber ICD implantation
TTE: Apical 4 chamber
TTE: Apical 2 chamber
TTE: Apical 3 chamber
TTE: Strain imaging
CMR: 4 chamber cine
CMR: 2 chamber cine
CMR: 3 chamber cine
CMR: Short axis cine at base level
CMR: Short axis cine at mid-papillary level
CMR: Short axis cine at apical level
Episode Schematics & Teaching
Hypertrophic Cardiomyopathy InfographicClick to enlarge!
The CardioNerds 5! – 5 major takeaways from the #CNCR case
Our patient was found to have Wolff-Parkinson-White (WPW) pattern. What are the diagnostic criteria for WPW pattern and how does it differ from WPW syndrome? How can you localize the accessory pathway using the EKG? WPW pattern refers to the presence of the below criteria on a patient's surface EKG in the absence of symptomatic arrhythmias. If symptomatic arrhythmias related to the accessory pathway occur, then it is WPW syndrome. Symptoms may include palpitations, shortness of breath, presyncope, syncope, and sudden cardiac death (SCD). Not all patients with accessory pathways have EKG findings as only 60-75% of accessory pathways are "manifest" (meaning they conduct antegrade from atria to ventricles or are bidirectional). Conversely, a "concealed" accessory pathway only conducts retrograde (from ventricles to atria) and would not be apparent on resting sinus EKG; these patients can have WPW diagnosed after a ventricular premature beat, ventricular pacing, or an EP study that shows retrograde conduction through the accessory pathway. The WPW pattern is diagnosed by the following EKG criteria: Short PR interval 120 ms. The degree of pre-excitation on EKG depends on the position (how much of the ventricular myocardium is depolarized by the accessory pathway) and depolarization speed of the accessory pathway (more rapid conduction leading to earlier ventricular depolarization and wider delta wave). We can use EKG findings to localize accessory pathways using the Arruda Criteria, which has an overall sensitivity of 90% and specificity of 99%. Note, patients who have a left-lateral bypass tract as the antegrade limb may not have delta waves on surface EKG, as the atrial impulse can take longer to reach the bypass tract than the AV node. What are the major mechanisms for WPW and how do they lead to early activation of the ventricles? How can this precipitate arrhythmias? Accessory pathways are abnormal congenital connections between the atria and ventricles when there is incomplete atrio-ventricular isolation during fetal development. They can be associated with congenital cardiac malformations like Ebstein anomaly. Depolarization of the ventricles occurs via the AV node and the accessory pathway simultaneously, leading to early depolarization of a portion of the ventricles and the characteristic delta wave. Depolarization through the His Purkinje system reaches the apex first and travels back up the ventricle, meeting the slower cell to cell conduction from the accessory pathway and causing termination of the impulses. The resulting QRS complex is essentially a "fusion beat" between the two sources. Accessory pathways often have more rapid conduction, but longer refractory periods than the AV node. If a PAC occurs when the accessory pathway is refractory, there will be antegrade conduction solely through the AV node. As the impulse travels through the ventricles it can conduct retrograde through the accessory pathway from V to A. This creates a reentrant pathway that results in atrioventricular reentrant tachycardia (AVRT), which accounts for up to 80% of SVT in WPW. Orthodromic AVRT (antegrade through AV node, retrograde through accessory pathway) accounts for 90-95% of AVRT in WPW. Other tachycardias can occur where the accessory pathway is a bystander and not required for initiation and maintenance of the arrhythmia like in AVRT. This includes atrial arrhythmias (e.g., atrial fibrillation, atrial flutter), ventricular tachycardia, and ventricular fibrillation. Atrial fibrillation is relatively common (~20%) in WPW syndrome patients. Atrial fibrillation with an accessory pathway can produce rapid ventricular rates due to unencumbered conduction via the accessory pathway. In these situations, QRS width and morphology may vary due to variable conduction via the AV node vs accessory pathway. Depending on the rate of conduction, the patient can degenerate into VF. A shorter refractory period places patients at the highest risk for VF. How do we risk stratify patients with WPW pattern? When would an EP study (EPS) be beneficial? What features are high risk on EPS and would warrant treatment? Patients who are asymptomatic are typically at low risk of sudden cardiac death. Those who do have SCD typically have symptoms at some point prior to arrest. Patients with intermittent loss of the delta wave on a beat-to-beat basis are likely at lower risk, as it suggests the accessory pathway lacks the ability for rapid AV conduction. However, persistent delta wave in asymptomatic patients may still be at low risk. The risk for SCD is thought to be due to rapid conduction of Afib down the accessory pathway leading to VF. Accessory pathways with shorter refractory periods are able to conduct at higher rates (shorter R to R intervals). Delta waves disappear when R to R interval is less than the refractory period, at which point the atrial impulse only conducts through AV node. Thus, the lower the HR that delta waves become intermittent, the lower the risk of SCD. We can start risk stratification in most patients noninvasively with a resting EKG and exercise EKG stress test, unless we clearly demonstrate intermittent delta wave at rest. If preexcitation persists even with maximal sinus heart rates, then an EPS is recommended.