Cardiac & Resuscitation, Exclusives, Patient Care

Prehospital Management of VF Arrest Due to Takotsubo Cardiomyopathy

This work, “Takotsubo VF_green," is a derivative of "Octopus catching pots, Tavira, Portugal" by GanMed64, used under CC BY 2.0. "Takotsubo VF_green" is licensed under CC BY-NC 4.0 by Paul M. Gallo and Andrew N. Hogan.

Prehospital Assessment

Medic 83 is dispatched to a private residence for a complaint of acute chest pain. An adolescent boy escorts you to his mother’s bedroom. Inside, crewmembers discover a distressed 37-year-old woman curled in the fetal position on her bed, clutching her chest, and screaming in pain. She is inconsolable and impossible to interview in her current state, but the crew manages to move her to a seated position and obtain a set of vital signs. Her heart rate is 145, blood pressure is 200/132, respiratory rate is 20, and oxygen saturation is 96%.

Related

Suddenly, the patient turns pale, collapses backwards onto the bed, and becomes acutely confused. She is still breathing spontaneously and has a palpable radial pulse, so she is quickly moved to the back of the medic unit for further treatment. Once she is loaded in the ambulance, neither crewmember is able to detect a pulse. Ventricular fibrillation (VF) is evident on the cardiac monitor (Figure 1).

Figure 1

Chest compressions and bag-mask ventilation are immediately initiated, pads are applied, and the patient is defibrillated with 360 J. During the first rhythm check, a strong and regular radial pulse is once again palpated. 

Vital signs obtained immediately after resuscitation include a heart rate of 109 and a blood pressure of 218/158. The patient is still poorly responsive with a GCS of 7 (E1V2M4), so bag-mask ventilation is continued. She is promptly transported to a nearby emergency department.

Hospital Course

The patient’s mental status has not significantly improved by the time Medic 83 arrives at the hospital. The ED physician decides to intubate her for airway protection. A 12-lead EKG performed in the ED does not reveal signs of acute ischemia. The patient’s initial serum troponin level is elevated, however, suggesting cardiac injury. She is admitted to the intensive care unit for further management.

Subsequent troponin measurements trend upward, and serial EKGs show new T-wave inversions. The patient is taken urgently to the cardiac catheterization lab due to concern for a developing acute myocardial infarction (AMI). Surprisingly, the cardiologist does not discover any evidence of obstructive coronary artery disease during the procedure. Radiography, however, demonstrates complete lack of movement of the distal left ventricular wall and a reduced ejection fraction of 35% (normally 55-60%). The patient is managed medically and eventually extubated.  Several days later, an echocardiogram shows an improved ejection fraction of 45-50%.

Discussion

This patient has a clinical picture diagnostic of Takotsubo cardiomyopathy (TC), a condition first identified in Japan in the early 1990s. TC is characterized by abnormal (or lack of) contraction of isolated regions of the left ventricular wall that cannot be explained by coronary artery disease. More than 80% of TC cases involve dysfunction of the left ventricular apex which causes this section of cardiac tissue to balloon when the rest of the ventricle contracts.1 The characteristic shape of the ballooning apex resembles a traditional Japanese octopus trap known as a ‘tako-tsubo’ (as seen in the lead photo). Impaired left ventricular contraction leads to decreased cardiac output. Complications such as acute heart failure, unstable dysrhythmias, or cardiogenic shock may result. Despite the potential for severe acute illness in cases of TC, the majority of affected patients completely return to baseline function within days to weeks of beginning medical therapy.2

Acutely, TC most commonly presents as chest pain or dyspnea and is clinically indistinguishable from AMI.3 In more than 70% of cases, an identifiable emotional or physical stressor precedes the onset of symptoms.1 Because of this correlation, Takotsubo cardiomyopathy is also known as ‘stress cardiomyopathy’ or ‘broken heart syndrome.’ Table 1 lists potential stressors associated with TC. It is thought that a surge of epinephrine-like chemicals released by the body in a moment of extreme stress might be responsible for the cardiac injury and dysfunction seen in TC.3


Fear, extreme anxiety, or panic
Stroke, intracranial bleed, or traumatic brain injury
Seizure
Asthma or COPD exacerbation
Drug overdose or withdrawal
Hyperthyroidism or adrenal crisis
Sepsis
Hypersympathetic states
Table 1. EMS-focused potential triggers of Takotsubo cardiomyopathy*
*Adapted from Lyon et al, 2016

In the case above, the patient was clearly in severe emotional distress at the time of EMS crew arrival.

More than 80% of cases of TC occur in females. Most patients are more than 50 years old at onset with an average age of approximately 65.5 Although the 37-year-old patient discussed earlier is notably younger than the typical TC patient, the condition has been observed in patients as young as 10 years old.6 Chronic psychiatric and neurological conditions, including bipolar disorder and epilepsy, have been associated with increased risk of developing TC.7

Even if a patient’s history strongly suggests a case of TC, ruling out the much more common diagnosis of AMI requires tests that are not available in the prehospital setting. Initial management of acute chest pain or dyspnea should proceed according to standard EMS protocols. In a stable patient, workup should begin with a 12-lead electrocardiogram (EKG). In nearly all patients, EKG abnormalities such as T wave inversions, Q waves, or left bundle branch blocks are seen within the first 24 hours.4 ST segment elevation similar in appearance to ST-elevation myocardial infarction (STEMI) is seen in 40-50% of cases of TC.5 Roughly 2% of all patients taken to the cardiac cath lab for suspected STEMI are instead diagnosed with TC.3 Thus, a patient with chest pain and concerning EKG changes in the prehospital setting should be treated per protocol for AMI until proven otherwise.

Unstable patients with TC generally present with recognizable clinical syndromes such as cardiogenic shock, congestive heart failure, or dysrhythmia.2 Standard interventions for these syndromes such as fluid administration, continuous positive airway pressure (CPAP), and cardioversion should be performed according to protocol. In the case described above, the patient was appropriately defibrillated for VF long before she was diagnosed with TC.

Between 15% and 25% of patients with TC are also affected by another anatomical abnormality known as left ventricular outflow tract obstruction (LVOTO).2 With LVOTO, the channel through which blood leaves the left ventricle becomes partially obstructed during ventricular contraction. This obstruction places additional strain on the ailing heart and leads to decreased cardiac output.8 Affected individuals are at increased risk of developing cardiogenic shock.9 Furthermore, they may paradoxically worsen with standard therapies for shock including CPAP or medications like epinephrine, norepinephrine, and dobutamine.10 Even nitroglycerin, a cornerstone of prehospital management for chest pain and pulmonary edema, can indirectly worsen cardiac output in cases of LVOTO by lowering cardiac preload.

Frustratingly, the paradoxical responses described above are most commonly noted after seemingly appropriate therapies have already been started. Identifying at-risk patients prior to treatment requires equipment that is not available in the field. In such cases, the best course of action is administration of a small fluid bolus to boost cardiac preload. Unless the patient has obvious evidence of pulmonary edema, this intervention is safe and potentially effective regardless of whether or not LVOTO is present.11

In summary, Takotsubo cardiomyopathy is a rare condition that may mimic acute myocardial infarction and present with life-threatening syndromes in the prehospital setting. The case of the 37-year-old woman described earlier highlights one possible presentation of the condition, despite the patient’s unusually young age. Although prehospital providers will rarely be able to definitively diagnose TC in the field, awareness of its existence is still beneficial. When patients with a history suspicious for TC fail to respond as expected to treatments for low cardiac output, the possibility of left ventricular outflow tract obstruction should be considered. Ineffective treatments can then be reassessed. EMS providers may also draw encouragement from the high rates of recovery and good outcomes of patients diagnosed with TC.

References

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  2. Ozaki K, et al. Manifestation of Latent Left Ventricular Outflow Tract Obstruction in the Acute Phase of Takotsubo Cardiomyopathy. Intern Med. 2016;55(23):3413-3420. doi: 10.2169/internalmedicine.55.7119. Epub 2016 Dec 1.
  3. Gianni M, et al. Apical ballooning syndrome or takotsubo cardiomyopathy: a systematic review. Eur Heart J. 2006 Jul;27(13):1523-9. doi: 10.1093/eurheartj/ehl032. Epub 2006 May 23.
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  9. De Backer O, et al. Prevalence, associated factors and management implications of left ventricular outflow tract obstruction in takotsubo cardiomyopathy: a two-year, two-center experience. BMC Cardiovasc Disord. 2014;14:147. doi: 10.1186/1471-2261-14-147.
  10. Soni P, et al. Takotsubo Cardiomyopathy With Left Ventricular Outflow Tract Obstruction and Shock. Chest. 2017 Oct;152(Suppl 4):A93. doi: 10.1016/j.chest.2017.08.123.
  11. Kurisu S, Kihara Y. Clinical management of takotsubo cardiomyopathy. Circ J. 2014;78(7):1559-66. doi; 10.1253/circj.CJ-14-0382. Epub 2014 Jun 12.