Takotsubo cardiomyopathy with left ventricular outflow tract obstruction...

A 69-year-old woman with no history of cardiovascular disease was admitted for acute chest pain, and signs and symptoms of cardiogenic shock. The onset of symptoms was preceded by a sudden stressful situation (she had been frightened by a mailman ringing on the doorbell during her nap). 

Physical and laboratory findings on admission:
- BP= 90/60 mmHg
- high-sensitivity troponin T 1007 ng/L (normal value < 14 ng/L)
- lactate of 32.4mg/dl (normal value < 7.21mg/dl)

X-ray confirmed lung congestion.

Figure 1 ECG (on admission) Sinus rhythm 93/min, ST-segment elevations in V1-V3, aVR, STD I, II, aVF

Echocardiography (on admission) showed akinesis and ballooning of the apical half of the left ventricle (LV) and reduced ejection fraction (LV EF 35-40%). Moreover, there was a 4/4 mitral regurgitation (MR) caused by systolic anterior motion (SAM) of the anterior mitral valve leaflet cusp and dynamic LV outflow tract obstruction (LVOTO) with a peak pressure gradient of 144mmHg. 

Video 1 TTE on admission with moderate to severe MiR and high gradient in LVOT

Figure 2  Severe left ventricular outflow tract obstruction (peak pressure gradient of 155 mmHg)

Coronary angiography showed no significant coronary artery stenosis, but left ventriculography confirmed the typical LV apical ballooning with grade 4/4 MR.

Video 2 Left ventriculography

Because of persisting cardiogenic shock, Impella CP was implanted before the patient left the cath lab. The device was inserted through the right femoral artery without complications, and the pump flow was set to P6 (2.3 L/min).

Video 3 Position of Impella CP after insertion

After transferring the patient to the cardiac intensive care unit, the patient condition rapidly improved, and pulmonary edema reverted. Her blood pressure was stable without vasopressors, lactate levels normalized, and no inotropes or diuretics were needed.

Second in-hospital day no SAM was seen on TTE, and decrease of mitral regurgitation was observed. There was a drop in hemoglobin from 11 to 8 g/dL, but without any recognizable source of bleeding or hemolysis. The levels of free hemoglobin remained normal (<6 mg/L) and Impella had an optimal position in the LV. Before the removal, the patient tolerated the flow rate reduction to 1,5l/ min (P2) with no change in the mean arterial blood pressure. 

However, within a few hours after the removal of the Impella, the patient developed mild pulmonary congestion and dyspnea. Arterial blood pressure, oxygenation, and serum lactate remained stable. Recurrence of LVOTO and a grade 2/4 MR due to SAM was observed. Swan-Ganz (SG) catheter was inserted for hemodynamic monitoring and precise guidance of fluid therapy. The improvement in hemodynamics was accompanied by the disappearance of the LVOT and pulmonary congestion. 

The patient was discharged on day 9 with a beta-blocker and ACE inhibitor on board.

Video 4 TTE on discharge (mild MiR, no SAM and LVOT obstruction)

One and half months after discharge, CMR was performed, and showed normal systolic function and volume of the LV, with no abnormalities in the LV kinetics and no late enhancement. 

Video 5 CMR 2-chamber view

‍Clinical context

Takotsubo cardiomyopathy (TC) is an acute condition characterized by reversible left ventricular dysfunction with paradoxical apical ballooning and relatively preserved contractility of basal segments.

It is often provoked by emotional or physical stress that leads to catecholamine surge, vasoconstriction of the coronary microcirculation, and myocardial stunning.

Although the disease has usually an uncomplicated course, 10-15% of patients develop cardiogenic shock that can result from the LV failure, dynamic LV outflow tract obstruction (LVOTO), or acute mitral regurgitation. 

Learning points

1) CS associated with TC represents a serious complication and a major therapeutic challenge, especially when the CS is caused by LVOTO.

2) ECG manifestations of TC are:
- ST elevations
- T inversions
- No reciprocal ST depressions
- absence of Q waves
- QT interval prolongation 

How to differentiate between STEMI ? ST elevations in TTC are most commonly in precordial leads, ST elevations in TTC are usually not present in V1, in contrast ST elevations are usually present in aVR.

3) Current treatment recommendations are based on clinical experience and expert opinions.
- Treatment of these patients is challenging since inotropes are inefficient or even detrimental in the presence of LVOTO.
- Volume expansion is problematic in the presence of pulmonary edema, diuretics or nitrates can exacerbate LVOTO, and beta-blockers are unsuitable for their hypotensive and negative inotropic effect.  

4) In such cases, mechanical circulatory support (MCS) remains the only therapeutic option.
- The axial-flow LV pump Impella may be a better choice of MCS type, because, in contrast to ECMO, it does not impede the LV filling.
- The optimal timing of MCS is still unclear. Clinical experience suggests that in the absence of complications, the Impella device should be left in place longer, even if the patient remains stable.

5) Adequate fluid management to optimize LV filling is crucial to the treatment of TC with CS.  Our case demonstrates the importance of precision fluid therapy guided by invasive hemodynamic monitoring with a Swan-Ganz catheter. Measurement of invasive hemodynamics can also be useful while weaning from MCS.

References

1. Ghadri JR, Wittstein IS, Prasad A, et al. International Expert Consensus Document on Takotsubo Syndrome (Part I): Clinical Characteristics, Diagnostic Criteria, and Pathophysiology. Eur Heart J. 2018;39(22):2032-2046. doi:10.1093/eurheartj/ehy076
2. Di Vece D, Citro R, Cammann VL, et al. Outcomes Associated With Cardiogenic Shock in Takotsubo Syndrome. Circulation. 2019;139(3):413-415. doi:10.1161/CIRCULATIONAHA.118.036164
3. Ghadri JR, Wittstein IS, Prasad A, et al. International Expert Consensus Document on Takotsubo Syndrome (Part II): Diagnostic Workup, Outcome, and Management. Eur Heart J. 2018;39(22):2047-2062. doi:10.1093/eurheartj/ehy077

Authors: Benak Ales, Sramko Marek, Janek Bronislav, Zelizko Michal, Kettner Jiri, Kautzner Josef.