Can Cardiac Recovery in Chronic Myocarditis Be Influenced by Training during LVAD Support?

Objective: A 6-month-old patient with massively impaired left ventricular function: EF 35% (ejection fraction) LVEDD (left ventricular end diastolic diameter) 44 mm–2 SD, VTI (velocity time integral) aortal < Pc 3, Speckle-tracking (ST) longitudinal strain (GLS) 4Ch -6.5%, 2Ch -6.4%). Biopsy revealed histological diagnosis of dilative cardiomyopathy, DD chronical myocarditis. Genetic testing was performed for known cardiomyopathy encoding genes. LVAD-Berlin Heart (BH, left ventricular assist device) implantation 2 days after Admission to hospital because of clinical deterioration. A weaning plan including cardiac muscle training was performed over 14 weeks.

Method: Follow-up using clinical and echocardiographic data (ST, VTI, and 3D-echocardiographic end diastolic [LVEDV], end systolic [LV-ESV], stroke volumes [LV-SV] and EF). Cardiac muscle training for 2 hour/day with reduction of the BH to 55/min for 3 weeks (phase A), extension to 4 hour/day for 2 weeks (phase B) and complete reduction to 55/min for 9 weeks (phase C). In the phase D: pump stop 30 minutes once per week under additional heparin bolus.

Results: The first intended reduction of the pump resulted in LV dilatation and increasing mitral incompetence. The training (phase A) was carried on and revealed an improvement of ST from 8% (GLS 2C) and 10% (GLS 4C) to 13% and respectively 11%. The VTIs were initially between Pc 3–10 and increased to Pc 10. Phase B showed at the beginning an increase of the LVEDV from 55 to 57 mL/m². At the end of the phase it remained constant with 59 mL/m² as well as VTI (10.Pc) and EF (36–32%). In phase D during pump stop, we assessed an increase of the VTIs and EF and an adequate increase of SV. ST proved a mild improvement (last test in the attached [Table 1]). Final hemodynamic testing in the cath. laboratory: BH50/min: CI (cardiac index) 4.1 mL/m²/min, CVS (central venous saturation) 60%, LVEDP (left ventricular end diastolic pressure) 8 mm Hg, Off BH 30 minutes: CI 3.6 mL/min/m², CVS 58%, LVEDP 10 mm Hg. The explantation of the device was successful.

Conclusion: Training of impaired cardiac muscle under LVAD in children with not acute myocarditis may be a possibility to prevent the direct way as bridge to transplant in selected patients. New echocardiographic tools may help assess improvement of function with impact on prognosis.

Table 1

Measurements phase D	Pump on	Pump off 15 min	Pump off 30 min
Heart rate/min	100	113	118
VTI pulmonal (cm)	15	16	16
VTI aortal (cm)	16	20	20
LVEDV (mL/m2)	79		76
LV-SV (mL)	18		15
EF%	44		50
GLS4CH%	−11	−10	−12
GLS2CH%	−10	−10	−15