Incidence of heart failure in infarcted rats that die spontaneously

Abstract

The present study reports for the first time the incidence of congestive heart failure (CHF) in previously infarcted rats that died spontaneously. Previously, pulmonary (PWC) and hepatic (HWC) water contents were determined in normal rats: 14 control animals were evaluated immediately after sacrifice, 8 placed in a refrigerator for 24 h, and 10 left at room temperature for 24 h. In the infarcted group, 9 rats died before (acute) and 28 died 48 h after (chronic) myocardial infarction. Thirteen chronic animals were submitted only to autopsy (N = 13), whereas PWC and HWC were also determined in the others (N = 15). Seven rats survived 48 h and died during anesthesia. Notably, PWC differed in normal rats: ambient (75.7 ± 1.3%) < control (77.5 ± 0.7%) < refrigerator (79.1 ± 1.4%) and there were no differences with respect to HWC. No clinical signs of CHF (dyspnea, lethargy or foot edema) were observed in infarcted rats before death. PWC was elevated in all chronic and anesthetized rats. HWC was increased in 48% of chronic and in all anesthetized rats. Our data showed that PWC needs to be evaluated before 24 h post mortem and that CHF is the rule in chronic infarcted rats suffering natural death. The congestive syndrome cannot be diagnosed correctly in rats by clinical signs alone, as previously proposed.

The Autonomic Nervous System, Sex Differences, and Chronobiology under General Anesthesia in In Vivo Experiments Involving Rats

“…However, approaches based on ECG recordings of animals in an anesthetic state are not ideal nor valid for HRV analysis due to significant heart rate fluctuations associated with impaired autonomic modulation of the heart [13,14]. In addition, anesthesia may contribute an important additional risk for animal mortality under some pathological conditions such as myocardial infarction and diabetes mellitus [15][16][17]. General anesthesia weakens autonomic function and baroreflex control.…”

Estudo da função em artérias de resistência de ratos pós-infarto do miocárdio.

“…Uma das características clínicas que marca a insuficiência cardíaca congestiva é a retenção de líquidos no pulmão e no fígado (Givertz et al, 2005). Na presente tese, a presença de congestão pulmonar e hepática foi inferida pelo teor de água (% água) presente nestes órgãos (Flumignan et al, 2006 Primeiramente, a artéria coronária localizada no septo interventricular (Lynch et al, 2006) e os terceiros ramos da artéria femoral (Sun et al, 1994;Trautner et al, 2006) foram dissecados e isolados com auxílio de lupa (Nikon SMZ 645, Melvile, New York, EUA). Após estarem livres do tecido conectivo, os mesmos foram colocados em uma placa de petri contendo solução de Krebs-Henseleit a 4º C (composição em mM: NaCl 118; KCl 4,7; NaHCO 3 25; CaCl 2 .2H 2 O 2,5; KH 2 PO 4 1,2; MgSO 4 .7H 2 O 1,2;…”