Takotsubo cardiomyopathy after pacemaker implantation.

Takotsubo cardiomyopathy (TTC) was first described by Japanese in 1990. The cardiomyopathy has got this name because the outline of the left ventricle looks like the octopus trap.[1] TTC is usually induced by physical triggers, emotional triggers, both of them or neither of them sometimes. The patients of TTC usually present the symptoms just like acute myocardial infarction or heart failure. Coronary angiography and left ventriculography are able to make the diagnosis and differential diagnosis. Although we have already good recognition of TTC, it might occur to the patients unexpectedly and sometimes preclude early diagnosis of it.

A 72-year-old female patient was admitted to hospital for sake of the second degree atrioventricular block (AVB) on ECG (Figure 1A) but without any symptom of fatigue and syncope. The patient had hypertension for several years and was on irregular use of metoprolol. She had also type 2 diabetes for five years and took metformin and insulin for long-term. She had no smoking and alcohol habits and the family history was not remarkably.

Figure 1.

The ECG evolution of the patient during hospitalization.

The vital signs were stable. Temperature: 36.2 °C, P: 51/min, R: 17/min, BP: 143/59 mmHg. There was no jugular vein distention, no pulmonary rales, no murmurs in the heart and no edema in lower extremities. The routine blood test, liver function test, renal function test, thyroid function test, electrolytes and troponin T (TnT) were all normal. Brain natriuretic peptide (BNP) was 340 pg/mL. The ECG showed second degree AVB with 2:1 conduction and the monitor in the cardiac care unit (CCU) further found intermittent third degree AVB. The echocardiography showed left atrium enlarged (4.34 cm), normal left ventricular end-diastolic diameter (LVDd) and left ventricular ejection fraction(LVEF). There were mild regurgitation of mitral, tricuspid and aortic valves. After exclusion of the reversible causes, the patient was implanted with permanent DDD pacemaker (Biotronic Estalla DR). The pacemaker worked well after the procedure (Figure 1B). However, in the first night after the procedure, the patient felt chest pain and short of breath. There were a little bit rales in the lungs and no murmurs were heard. The ECG showed the atrial sensing-ventricular pacing rhythm without dynamic ST-T alteration (Figure 1C). But the TnT was elevated to 0.169 ug/L. Thus, the patient accepted furosemide intravenously and painkillers and the symptoms were alleviated gradually. In the morning of the second day, the TnT was 0.535 ug/L and 0.461 ug/L in 1 hour apart. The ECG in the morning demonstrated that atrial sensing-ventricular pacing rhythm with T waves inversion in the pericardial leads (Figure 1D). Considered the possibility of myocardial ischemia, we performed angiography. Consequently, there were mild lesions in the coronary arteries and ventriculography found the anterior, apex and inferior wall were almost akinetic whereas the basal part of the left ventricle was hyperkinetic (Figure 2 and 3). The UCG which was performed after ventriculography demonstrated that LVDd 5.5 cm and LVEF 40%. The middle-lower part of the left ventricle was hypokinetic. The result confirmed the diagnosis of TTC. Why did it occur to this patient? We tracked the history in details and eventually found that the patient felt pain, nervous and anxiety during the procedure of pacemaker implantation but she did not tell her feeling to the doctor. The physical and emotional stress in the operation triggered the TTC. After 10 days, the patient took another UCG and the result did not improve significantly. The patient took furosemide, spirolactone and metoprolol succinate for long-term. Four months later, the patient came back to our outpatient department for the visit. UCG showed the recovery of the left ventricular motion and LVEF was elevated to 50%.

Figure 2.

The end-systolic ventriculography.

Figure 3.

The end-diastolic ventriculography.

The existing registry data might underestimate the incidence of TTC for sake of the possibility of pre-hospital sudden death.[2]–[4] Usually it is more prevalent in postmenopausal women than men,[5] while it is the opposite in Japan.[6] It has been demonstrated that physical stress accounts for 36% of the trigger factors while the emotional stress accounts for 27.7%. Approximately 28.5% patients had no evident triggers whereas 7.8% patients had both the triggers.[5] Furthermore, male patients are more likely to have physical triggers than women.[5],[7] As to this patient, the painful feeling, anxiety and nervousness due to pacemaker procedure-a small traumatic surgery further caused TTC, which we have never met before and beyond our expectation.

TTC has been classified to four types: apical type, midventricular type, basal type and focal type.[5] Among them, apical type is the most prevalent, about 75%–80%. However, there was a quite small proportion of biventricular type, which accounts for less than 0.5% by clinical diagnosis, whereas it can be detected by cardiac magnetic resonance in about 33% patients.[4] According to the result of ventriculography, the reported patient was categorized to apical type. Nonetheless, we thought the extent of akinetic area were larger than the typical one. TTC usually has the similar evolution of ECG and biomarkers with ST segment elevation myocardial infarction. Nevertheless, this patient has been implanted the permanent pacemaker, thereby the typical alteration of ECG has been masked by the ventricular pacing rhythm. Thus, it precluded the early recognition of the problem. Although the cardiac dysfunction due to TTC is usually reversible, there is about 7.1% major adverse cardiovascular and cerebral events (MACCE) within 30 days and 5.6% all-cause death per patient-year in long-term follow-up.[5] The angiotensin converting enzyme inhibitor, angiotensin receptor blockers and β blocker have been improved benefit to clinical prognosis.[5],[8] It is do necessary to establish a long-term schedule for observation and assessment of the TTC patients.