Ventricular Fibrillation Complicating Acute Myocardial Infarction: Results
Group 1 (Table 1) included seven male patients with ages ranging from 39 to 79 years (mean, 58 years). Two patients had had previous myocardial infarction, four had effort-induced or unstable angina, and two were free of cardiac symptoms. The AMI was anterior in three patients and inferior, inferolateral, extensive posterior, and anteroseptal wall in the remaining four patients, respectively. None of these was given diuretics prior to the onset of VF. Six patients developed VF during stage 1 of infarction, and in the remaining patient, VF was documented following the appearance of pathologic Q waves (Table 2). The mean duration of time between admission and VF occurrence was 2.5 hours (range, 0 to 16 hours). An exception is patient 7, where VF was observed 16 hours after admission. Of the seven patients, only one (patient 3) had recurrent episodes of VF. Direct-current shocks were remarkably efficient in the restoration of sinus rhythm. One patient died from cardiogenic shock on the fifth day of hospitalization (in-hospital mortality, 14 percent). Additional complications in this group were reinfarction (one patient) and atrial arrhythmias (two patients).
Group 2 (Table 3) included 27 patients (22 men) with ages ranging from 42 to 84 years (mean, 62 years), (p>0.2; not statistically significant vs group 1). Previous cardiac disease was found in 15 patients (56 percent). Three of the patients were receiving diuretic treatment because of hypertension, with normal levels of electrolytes upon admission. The site of infarction was anterior (seven patients), inferior (seven patients), anteroseptal (six patients), and inferolateral and extensive posterior in the remaining seven patients. Type 2 VF appeared once pathologic Q waves were already apparent (electrocardiographic stage 2), with the exception of patients 4 and 26, in whom the arrhythmia was documented in the setting of stage 1 (p = 0.00015; statistically significant vs group 1). The mean duration of time between admission and the onset of the arrhythmia was 5.7 hours (range, 30 minutes to 17 hours) (p>0.1; not statistically significant vs group 1). Fourteen patients (52 percent) had a single episode of VF which was responsive to one to five direct-current shocks. In the remaining 13 patients (48 percent), recurrent episodes appeared, with an average of four episodes per patient (range from 2 to 15 episodes) (p = 0.4; not statistically significant vs group 1). Direct-current shocks were given more frequently to patients in group 2 (1.27 direct-current shocks per VF attack in group 2 vs one direct-current shock in group 1); however, this difference was not statistically significant (p = 0.5). In one instance, spontaneous conversion of tachyarrhythmia was observed. Three patients died (in-hospital mortality, 11 percent; not statistically significant vs type 1); deaths were related to reinfarction, pump failure, or both. Late morbidity included severe left-sided heart failure (two patients) and atrial arrhythmias (four patients).
Table 2—Clinical Correlates
| Data | Group 1 | Group 2 | p Value* |
| No. of patients | 7 | 27 | |
| Age, yr | 58± 11 | 62 ±10 | NS |
| Phase of AMIt | |||
| Stage 1 | 6 | 2 | |
| Stage 2 | 1 | 25 | 0.00015 |
| Onset of VF, hours after admission | 2.5 ±5 | 5.7±5 | NS |
| No. of episodes | 1.3±0.7 | 2.4±2.8 | NS |
| No. of DC shocks per VF | 1.3±0.7 | 3.1±3.2 | NS |
Table 3—Clinical and Electrocardiographic Data on 27 Fatienis with Type 2 VF Complicating AMI
| Pbtient, Sex, Age (yr) |
CardiacRisk
Factors* |
PreviousCardiac
Diseaset |
Phaseof
AMI |
Localization of AMI* | Onset of VF, hours after admission | No. of Episodes | Total No. of DC Shocks | Complications!! |
| 1,M,70 | 2 | EX/AN | 1 | 2 | 3 | |||
| 2,M,59 | AP | 2 | EX/AN | 0.5 | 7 | 7 | ||
| 3,M,71 | 2 | EX/AN | 0.5 | 1 | 1 | IW AMI; death | ||
| 4,F,54 | AH; SM; DM | MI | 1 | ASW | I | 1 | 1 | CHB; death |
| 5,F,42 | SM; DM | 2 | IW | 1 | 3 | 3 | ||
| 6,M,84 | DM | AP; MI | 2 | IW | 8 | 1 | 1 | PE |
| 7,M,50 | SM | 2 | IN/LA | 0.75 | 5 | 7 | ||
| 8,F,70 | AH | 2 | ASW | 3 | 1 | SC§ | ||
| 9,M,59 | AH; DM | MI | 2 | IN/LA | 2 | 4 | 4 | |
| 10,F,64 | AH | 2 | IW | 10 | 2 | 2 | ||
| 11,M,52 | AH; SM | 2 | EX/AN | 17 | 1 | 3 | SVT | |
| 12,M,71 | AH; SM | AP | 2 | IW | 4 | 1 | 1 | |
| 13,M,70 | MI | 2 | IN/LA | 11 | 2 | 2 | ||
| 14,M,73 | AH | AP; MI | 2 | ASW | 3.5 | 1 | 3 | SVT; reinfarction |
| 15,M,47 | SM | AP | 2 | EX/PO | 14 | 3 | 3 | |
| 16,M,53 | AP; MI | 2 | IN/LA | 3 | 1 | 3 | ||
| 17,M,66 | 2 | EX/AN | 12 | 1 | 1 | |||
| 18,F,74 | AH; SM | 2 | EX/PO | 10 | 1 | 1 | ||
| 19,M,72 | DM | MI | 2 | IW | 4 | 2 | 2 | CS; death |
| 20,M,59 | AP | 2 | IW | 2 | 1 | 2 | ||
| 21,M,62 | SM | MI | 2 | EX/AN | 3 | 1 | 1 | |
| 22,M,67 | AH | 2 | IW | 17 | 2 | 2 | Reinfarction | |
| 23,M,47 | AP | 2 | EX/AN | 10 | 3 | 5 | PE; SVT | |
| 24,M,60 | Hyperlipidemia | AP; MI | 2 | ASW | 2 | 2 | 5 | |
| 25,M,60 | 2 | EX/PO | 2 | 1 | 1 | |||
| 26,M,66 | AH; SM | 1 | ASW | 1.5 | 15 | 17 | ||
| 27,M,49 | SM; hyperlipidemia | MI | 2 | ASW | 9 | 1 | 2 | SVT |
Category: Myocardial Infarction
Tags: electrocardiographic, myocardial infarction, ventricular fibrillation