A 74-year-old woman was referred for pulmonary vein isolation for paroxysmal atrial fibrillation. Other than anxiety, her history was unremarkable. In the cardiac electrophysiology laboratory, we performed continuous analysis of heart rate variability during sinus rhythm. The low (0.04–0.15 Hz) and high (0.15–0.4 Hz) frequency bands correspond primarily to sympathetic and parasympathetic tone, respectively.
Baseline:
Sympathetic tone was high compared to parasympathetic tone. The patient was intubated 60 mins before onset of left ventricular (LV) dysfunction (T-60).
T-50:
Transient accelerated idioventricular rhythm suggested high oxidative stress, which can cause excitation-contraction uncoupling.
T-40:
ST elevations (1.5–3.0 mm) in the anteroseptal and lateral leads were consistent with prior reports of Takotsubo cardiomyopathy (Figure 1-AB). Transthoracic echocardiography revealed no signs of LV dysfunction.
FIGURE 1.
Neurocardiac changes before and during the onset of Takotsubo cardiomyopathy.
T-30:
An increase (110-fold) in parasympathetic tone reduced the heart rate (Figure 1-C).
T-20:
Both sympathetic and parasympathetic tone returned to baseline, and ST segments normalized without echocardiographic signs of LV dysfunction.
T-15:
Total power increased in the frequency domain, primarily due to parasympathetic tone.
T-10:
A shift to the dominant parasympathetic tone was associated with echocardiographic evolution of LV apical akinesis/ballooning. The absence of corresponding ST changes may reflect excitation-contraction uncoupling and transmural electrophysiological changes that occur circumferentially to cancel opposing ECG vectors.
Emergent angiogram ruled out coronary occlusion and vasospasm. Ventriculogram revealed preserved basal LV contraction with apical ballooning (Figure 1-D), 25% ejection fraction, and 20 mmHg end-diastolic-pressure. The patient was managed with β-adrenergic blockers. Serum troponin levels peaked (2.3 ng/mL) and ejection fraction recovered (65%) within four weeks.
These findings represent a prototypical case of Takotsubo syndrome and may implicate a potential mechanistic role of the parasympathetic nervous system, which deserves further study. This case also highlights the importance of addressing patient anxiety before procedures.
Acknowledgments
This work was presented at a highlighted oral session titled “Provocative Cases” on July 30, 2021 at the 2021 Heart Rhythm scientific sessions in Boston, MA.
Footnotes
Disclosures: The authors have no conflicts of interest. The research analyses were supported in part by grant awards (to DD) from the National Institutes of Health (NIH) Common Fund Director’s New Innovator Award DP2 HL157941, NIH National Heart, Lung, and Blood Institute (NHLBI) 4R00HK130662, American Heart Association (AHA) Machine Learning 19AIML34930039, AHA Transformational Project Award 19TPA34850151, Department of Defense (DOD) W81XWH-191-0640 #PR182372, and DOD W81XWH-201-0701 #PR191442.
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