How to manage various arrhythmias and sudden cardiac death in the cardiovascular intensive care

Abstract

In the clinical practice of cardiovascular critical care, we often observe a variety of arrhythmias in the patients either with (secondary) or without (idiopathic) underlying heart diseases. In this manuscript, the clinical background and management of various arrhythmias treated in the CCU/ICU will be reviewed. The mechanism and background of lethal ventricular tachyarrhythmias vary as time elapses after the onset of MI that should be carefully considered to select a most suitable therapy. In the category of non-ischemic cardiomyopathy, several diseases are known to be complicated by the various ventricular tachyarrhythmias with some specific mechanisms. According to the large-scale registry data, the most common arrhythmia is atrioventricular block. It is essential for the decision of permanent pacemaker indication to rule out the presence of transient causes such as ischemia and electrolyte abnormalities. The prevalence of atrial fibrillation (AF) is very high in the patients with heart failure (HF) and myocardial infarction (MI). AF and HF have a reciprocal causal relationship; thus, both are associated with the poor prognosis. Paroxysmal AF occurs in 5 to 20% during the acute phase of MI and triggered by several specific factors including pump failure, atrial ischemia, and autonomic instability. After the total management of patients with various arrhythmias and basic heart diseases, the risk of sudden cardiac death should be stratified for each patient to assess the individual need for preventive therapies. Finally, it is recommended that the modalities of the treatment and prophylaxis should be selected on a case-by-case basis in the scene of critical care.

Keywords: Acute myocardial infarction; Arrhythmias; Cardiovascular intensive care; Congestive heart failure; Electrical storm.

Fig. 1

The contents of the arrhythmias in the patients who were admitted to the CCU/ICU in the Tokyo CCU Network for the treatment of arrhythmias in 2014. Those correspond to approximately 10% of the total patients. The most common arrhythmia was AV block, which was followed by ventricular tachycardia and atrial fibrillation

Fig. 2

A case (67 years old, male) with a VT/VF storm that emerged during the acute phase of an anterior infarction (4th day). Left panel: The monitored ECG recording revealed that this polymorphic tachycardia was always initiated by PVCs with exactly the same QRS morphology with a relatively narrow configuration. Right panel: Detailed LV mapping demonstrated that the Purkinje potentials (indicated by the red arrows) from the posterior fascicular region preceded the onset of the QRS complex by 55 ms during the PVCs. HBE His bundle electrogram, P Purkinje potential, RBB right bundle branch potential, H His potential

Fig. 3

Monitored ECG recordings (three episodes) showing a torsades de pointes (Tdp) tachycardia in a patient with an AV conduction disturbance and hypopotassemia (83 year old, female). Each episode of the Tdp tachycardia was preceded by a short-long-short sequence of the R-R intervals created by isolated ventricular premature contractions

Fig. 4

A representative case of paroxysmal AV block (81 years old, male). a 12-lead ECG before the syncope. b The monitor ECG during a syncopal episode in the CCU (for further explanation, see the text)

Fig. 5

The relationship between the severity of the CHF and the prevalence of AF. The data were collected from randomized trials of patients with CHF with various severities of heart failure (NYHA classification). The prevalence of AF is well correlated with the severity of CHF (cited from reference [39])

Fig. 6

Association between atrial fibrillation and the all-cause mortality and cardiovascular and renal disease, with a summary of the relative risks of each outcome examined (cited from reference [41])

Fig. 7

Comparative presentation of the hemodynamic variables between the patients with PAF (group 1) and those without PAF (group 2). The variables were measured during sinus rhythm, within 24 h before the onset of the PAF in group 1, and at the time of admission prior to various therapeutic interventions in group 2 (cited from reference [46]). PAP pulmonary artery pressure, PCWP pulmonary capillary wedge pressure, CVP central venous pressure, CI cardiac index, HR heart rate

Fig. 8

A diagnostic and therapeutic flowchart of the follow-up in the patients with tachycardia induced cardiomyopathy. For further details, see the text. TICM: tachycardia induced cardiomyopathy. TMCM: tachycardia-mediated cardiomyopathy (this figure was modified from Fig. 1 of reference [57])