Long RP tachycardia with cycle length alternans and QRS alternans. What is the mechanism?

Long RP tachycardia with cycle length alternans and QRS alternans. What is the mechanism?
Acta Cardiol. 2017 Aug 22;:1-2
Authors: Mohanan Nair KK, Namboodiri N, Abhilash SP, Valaparambil A
PMID: 28826338 [PubMed - as supplied by publisher]

Source: Acta Cardiologica - August 23, 2017 Category: Cardiology Tags: Acta Cardiol Source Type: research