[Rhythmic profiles of the late phase of acute myocardial infarction as a function of age]
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A L Bordalo e Sá1, M J Correia, L Neves
1UTIC-Arsénio Cordeiro, Hospital de Santa Maria, Lisboa.
Insights
Older age is a significant risk factor for ventricular arrhythmias after acute myocardial infarction (AMI). While most patients had a low risk, elderly individuals showed a higher incidence of premature ventricular beats (PVB).
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Context:
- Late phase of acute myocardial infarction (AMI) poses risks for cardiac arrhythmias.
- Understanding risk factors for ventricular arrhythmias is crucial for patient management post-MI.
Purpose:
- To determine the incidence of ventricular arrhythmias in the late phase of AMI.
- To compare the occurrence of arrhythmias with clinical parameters including age, sex, AMI localization, ventricular function (Killip classes), maximal creatinokinase (CK max), and sinus tachycardia.
Summary:
- A prospective study of 153 AMI survivors found that 24% experienced premature ventricular beats (PVB) ≥3/h.
- Older age (≥70 years) was significantly associated with a higher incidence of PVB compared to younger groups.
- Ventricular function (Killip class) showed a trend towards more arrhythmias in heart failure, but age was the strongest predictor.
Impact:
- Identifies age as a key risk factor for late-phase ventricular arrhythmias post-AMI.
- Informs risk stratification and potential interventions for elderly AMI patients.
- Highlights the need for closer monitoring of older individuals following myocardial infarction.
Objectives:
To evaluate the incidence of ventricular arrhythmias in the late phase of acute myocardial infarction (AMI) and to compare it with the following clinical parameters: age, sex, AMI localization, ventricular function (Killip classes), maximal creatinokinase (CK max) and the presence of sinus tachycardia.
Design:
Prospective study, during a period of 31 months, of a non-selected group of patients with AMI.
Setting:
Coronary Care Unit (UTIC-Arsénio Cordiero).
Patients:
Non-selected group of 153 patients with acute myocardial infarction who survived the second week of disease.
Material And Methods:
24-hour Holter ECG performed between the 4th and the 25th day of AMI. The patients were divided into two groups according to the hourly frequency of premature ventricular beats (PVB): less than 3 per hour (PVB less than 3/h) and 3 or more per hour (PVB greater than or equal to 3/h).
Results:
PVB greater than or equal to 3/h occurred in 36 patients (24%). There was no differences in the occurrence of ventricular arrhythmias between sex, AMI localization, AMI size evaluated by CK max, and the presence of sinus tachycardia. Patients in Killip class III had more ventricular arrhythmias (67%) than patients in Killip class I (23%) (p less than 0.005), in Killip class II (18%) (p = 0.007), and in Killip IV (0%) (p = 0.017). In patients with serious left ventricular failure (classes III + IV) the ventricular arrhythmias were not significantly higher (40%) than in patients without serious left ventricular failure (classes I + II) (22%) (chi 2 = 2.5; p less than 0.25 NS). Patients with less than 41 years old had less PVB greater than or equal to 3/h (4%) than patients between ages 41-69 (24%) (p less than 0.05), and than patients over 70 years old (47%) (p = 0.00075).
Conclusions:
The majority of patients (76%) showed a low risk rithmic profile (PVB less than 3/h) in the late phase of AMI. Among all parameters the age of the patients was the one best related to the occurrence of ventricular arrhythmias. Sex, AMI localization, AMI size, and the presence of sinus tachycardia were not related to the presence of PVB. A slight tendency was found in patients with heart failure to have more PVB. On the other hand the elder group carried a statistically significant risk factor for a higher occurrence of ventricular premature beats.