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Does sex influence the incidence or severity of reperfusion-induced cardiac arrhythmias?

Dow JS, Bhandari A, Hale SL, Kloner RA - Springerplus (2015)

Bottom Line: Our purpose was to determine if sex influences either the incidence or severity of reperfusion-induced arrhythmias resulting from a brief coronary occlusion.Analysis showed no other significant differences in ventricular arrhythmias between the two groups.Among survivors there was no difference in any other arrhythmic parameters measured.

View Article: PubMed Central - PubMed

Affiliation: The Heart Institute, Good Samaritan Hospital, Los Angeles, CA USA.

ABSTRACT

Unlabelled: Whether sex affects the acute phase of myocardial ischemia in experimental animal models is currently being debated. Our purpose was to determine if sex influences either the incidence or severity of reperfusion-induced arrhythmias resulting from a brief coronary occlusion. Male and female Sprague-Dawley rats were assigned to the study. Anesthetized animals were subjected to a 5-minute coronary artery occlusion followed by 5 minutes of reperfusion. Mortality differed by sex: 10/27 (37%) of males died due to VT/VF while only 1/16 females (6%) died due to VT/VF (p = 0.033). Quantitative analysis of the electrocardiogram was performed on data acquired from 17 male and 15 female survivors. Analysis showed no other significant differences in ventricular arrhythmias between the two groups.

Conclusion: Lethal reperfusion-induced arrhythmias led to a higher mortality in male rats versus female rats. Among survivors there was no difference in any other arrhythmic parameters measured.

No MeSH data available.


Related in: MedlinePlus

Percentage mortality due to sustained ventricular tachycardia/ventricular fibrillation in male and female rats. Mortality was higher in males (37%) compared to females (6%). As per Table 1, mortality was substantially greater in males (p = 0.033) by Fisher’s Exact test.
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Fig1: Percentage mortality due to sustained ventricular tachycardia/ventricular fibrillation in male and female rats. Mortality was higher in males (37%) compared to females (6%). As per Table 1, mortality was substantially greater in males (p = 0.033) by Fisher’s Exact test.

Mentions: Of the 33 male rats, one was excluded due to frequent and substantial arrhythmias during stabilization, one died during reperfusion due to a technical problem, and 4 were excluded because the area at risk (AR) was < 15% of the LV (prospective exclusion criterion). Of 19 female rats, one was excluded due to technical problems during the surgical preparation, and 2 were excluded because the AR was < 15% of the left ventricle. Of the remaining 27 males and 16 females, the mortality rate due to lethal VT/VF was higher in the male group (10 deaths; 37%) compared to the female group (1 death; 6%, p = 0.033, Table 1, Figure 1). Quantitative analysis of the ECG (Standard limb lead II) was performed on the 17 male and 15 female survivors. This analysis did not show any other significant quantitative differences in ventricular arrhythmias between the two groups (Table 2). One male rat had a 3.6 s run of transient VF; no female had transient VF. We chose to use age-matched rats in this study. Average body weight in the males (445.4 ± 9.7 gm) was significantly higher (p < 0.0001) than in females (288.2 ± 2.8 gm). Heart rate (HR), mean arterial pressure (MAP), and body temperature (T) were similar (p = ns) between the groups (Table 3). The AR was similar in size (p = ns) in the males (32.4% ± 01.9) and females (33.0% ± 02.2).Table 1


Does sex influence the incidence or severity of reperfusion-induced cardiac arrhythmias?

Dow JS, Bhandari A, Hale SL, Kloner RA - Springerplus (2015)

Percentage mortality due to sustained ventricular tachycardia/ventricular fibrillation in male and female rats. Mortality was higher in males (37%) compared to females (6%). As per Table 1, mortality was substantially greater in males (p = 0.033) by Fisher’s Exact test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4352162&req=5

Fig1: Percentage mortality due to sustained ventricular tachycardia/ventricular fibrillation in male and female rats. Mortality was higher in males (37%) compared to females (6%). As per Table 1, mortality was substantially greater in males (p = 0.033) by Fisher’s Exact test.
Mentions: Of the 33 male rats, one was excluded due to frequent and substantial arrhythmias during stabilization, one died during reperfusion due to a technical problem, and 4 were excluded because the area at risk (AR) was < 15% of the LV (prospective exclusion criterion). Of 19 female rats, one was excluded due to technical problems during the surgical preparation, and 2 were excluded because the AR was < 15% of the left ventricle. Of the remaining 27 males and 16 females, the mortality rate due to lethal VT/VF was higher in the male group (10 deaths; 37%) compared to the female group (1 death; 6%, p = 0.033, Table 1, Figure 1). Quantitative analysis of the ECG (Standard limb lead II) was performed on the 17 male and 15 female survivors. This analysis did not show any other significant quantitative differences in ventricular arrhythmias between the two groups (Table 2). One male rat had a 3.6 s run of transient VF; no female had transient VF. We chose to use age-matched rats in this study. Average body weight in the males (445.4 ± 9.7 gm) was significantly higher (p < 0.0001) than in females (288.2 ± 2.8 gm). Heart rate (HR), mean arterial pressure (MAP), and body temperature (T) were similar (p = ns) between the groups (Table 3). The AR was similar in size (p = ns) in the males (32.4% ± 01.9) and females (33.0% ± 02.2).Table 1

Bottom Line: Our purpose was to determine if sex influences either the incidence or severity of reperfusion-induced arrhythmias resulting from a brief coronary occlusion.Analysis showed no other significant differences in ventricular arrhythmias between the two groups.Among survivors there was no difference in any other arrhythmic parameters measured.

View Article: PubMed Central - PubMed

Affiliation: The Heart Institute, Good Samaritan Hospital, Los Angeles, CA USA.

ABSTRACT

Unlabelled: Whether sex affects the acute phase of myocardial ischemia in experimental animal models is currently being debated. Our purpose was to determine if sex influences either the incidence or severity of reperfusion-induced arrhythmias resulting from a brief coronary occlusion. Male and female Sprague-Dawley rats were assigned to the study. Anesthetized animals were subjected to a 5-minute coronary artery occlusion followed by 5 minutes of reperfusion. Mortality differed by sex: 10/27 (37%) of males died due to VT/VF while only 1/16 females (6%) died due to VT/VF (p = 0.033). Quantitative analysis of the electrocardiogram was performed on data acquired from 17 male and 15 female survivors. Analysis showed no other significant differences in ventricular arrhythmias between the two groups.

Conclusion: Lethal reperfusion-induced arrhythmias led to a higher mortality in male rats versus female rats. Among survivors there was no difference in any other arrhythmic parameters measured.

No MeSH data available.


Related in: MedlinePlus