Cardiac Electrical Vulnerability after Acute Myocardial Infarction Associated with Respiratory Infections

Abstract

Heart rate variability and the presence of late potentials are independent predictor factors for cardiac death and electrical vulnerability of the ischemic myocardium, especially after myocardial infarction(MI). Respiratory infection are known to be associated with MI both through direct action of the pathogen and by altering the hemodynamic status, through tachycardia and a rise in myocardial oxigen demand. Our paper wants to highlight that respiratory infection during subacute and late recovery phase of myocardial infarction can aggravate the electrical vulnerability of the myocardium and increases the arrhythmic risk. We analysed heart rate variability and the presence of late potentials on signal-averaged ECG in patients who developed acute respiratory infection after MI. All parameters of heart rate variability were signifficantly decreased in our target group. Incidence of late potentials did not differ between the two groups, meaning that the electrophysiological substrate of arrhythmias was not influenced by respiratory infection. Ventricular arrhythmias were more severe and frequent in the infection group. Respiratory infectious disease in early and late recovery phase after acute myocardial infarction, increases the risk of life threatening arrhythmias. It must be emphasized the need to consider prevention and early treatment of respiratory viral or bacterial infections, particularly in patients with cardiac ischemic disease.

Predictive Value of Several Echo Parameters for Cardiovascular Events in Hemodialysis Patients with Mid-range and Preserved Ejection Fraction Heart Failure

“…Also the timeframe duration was less than 2.5 years, influencing the lack of association between some echo parameters and cardiovascular mortality. Hemodialysis patients are exposed to a higher risk of ischemic and arrhythmic events [19,20]. High blood pressure precipitates LVH which also represent a predictor for sudden cardiac death due to arrhythmic and ischaemic events [21,22].…”

“…The new Tissue Doppler and Speckle tracking techniques can add more prognostic value for us in order to understand and treat the dialyzed patient involved in the pathophysiological continuum between kidney and heart [8][9][10][11][12][24][25][26]27]. Also, in some studies, arterial stiffness assessed by carotid femural pulse wave velocity [28], late potentials related arrhythmias [19], low EF or low RR variability [19], were associated with higher mortality risk and are useful marker because they are correlated with overall cardiovascular mortality [29,30], used even in hemodialysis patients. The LV dysfunction is evident in almost half of ESRD patients starting dialysis and can be induced by hemodialysis itself [6,29,31,32].…”

RR Variability in Acute Coronary Syndromes

“…Data sets of the HRV in the frequency domain were submitted to a rapid Fourier transformation algorithm in order to separate signal areas into high-frequency (RRIHF) (0.15-0.5 Hz) and low-frequency (RRILF) (0.01-0.15 Hz) bands (expressed in ms). The spectrum of frequency variation is recorded on a 2 minute time frame [4,5].…”

“…To establish the sympathetic/parasympathetic balance we used the oscillating values from the frequency domain analysis, where the parasympathetic tone modulates the HRV with oscillations at the RRIHF and corresponds to the respiratory frequency and the RRILF reflects a combination of factors that include influences of both parasympathetic and sympathetic effects [4][5][6][7].…”

Sudden cardiac death in patients with myocardial infarction: 1.5 primary prevention

“…In addition, ischemia and hypoxia after an MI will lead to the increase of myocardial vulnerability and play an important role in the generation of re-entries [53]. HRV and the presence of the high average late potentials on ECG are also independent predictors of SCD and ischemic myocardial vulnerability after an MI [54].…”