Discussion
CVS is infamous for its malignant, quite relatively uncommon,
arrhythmogenic complications3,6,7. Recognizing and
preventing this potential lethality with medical treatment and device
therapy are a major cornerstone in the management of CVS
patients8. The American Heart Association/American
College of Cardiology/Heart Rhythm Society guidelines in 2017 have
specifically addressed the issue of ICD placement in CVS
patients9. ICD received a class IIa recommendation
when medical therapy has failed in preventing CVS-induced SCD, and a
class IIb recommendation in addition to medical therapy after a first
episode of CVS-induced SCD. However, ICD remains under-utilized in this
setting3 .
Though uncommon, the presence of a “shark fin” pattern on ECG (Fig.
1), consisting of the blurring of the QRS and T-wave with significant
ST-elevation, indicates a large burden of myocardial
ischemia5. Known to be a high-risk pattern, this rare
ECG finding predicts cardiogenic shock and mortality5.
A recently published report showed that the “shark fin” pattern is
associated with ventricular arrhythmias and cardiogenic shock in
Takotsubo syndrome10. Miranda et al reported the case
of a 53-year-old patient, where a transient “shark fin” pattern could
have been caused by left main coronary spasm11.
Our case suggests that there may be an association between CVS-induced
ventricular arrhythmias and certain ECG patterns such as the QRS-ST-T
“shark fin” pattern. This specific pattern may predict cardiac sudden
death during vasospasm. We hypothesize that this “shark fin” pattern,
previously reported as a life-threatening pattern in myocardial
infarction4, may also indicate a lethal arrhythmogenic
propensity in CVS patients. Therefore, if such a pattern is documented
during CVS, we recommend implementing aggressive treatment strategies
with medical and device therapy. Specifically, an ICD should be
recommended despite stenting the potential target lesion, and that
because of the diffuse and recurrent nature of CVS over time, as
demonstrated in our observation where severe spasm recurred seven years
after the initial episode.