Cardiotoxicity is a rare, but well-recognized complication of treatments with the anti-cancer drug 5-fluorouracil (5FU). The underlying mechanism, however, is not fully elucidated. A spasm of the coronary arteries is often considered to be the leading cause of myocardial ischemia and decreased contractility associated with 5FU. As spasm cannot account for all reported adverse cardiac effects, the present study was undertaken to search for alternative mechanisms. Groups of six rabbits were given either a single intravenous dose of 50 mg/kg 5FU or four intravenous doses of 15 mg/kg 5FU at 7-day intervals. A third group served as control. The heart was removed shortly after death or scheduled sacrifice of the animals, to perform macroscopic and microscopic examinations of the heart and to evidence apoptosis by the TUNEL method. Following a single dose of 50 mg/kg 5FU, all animals rapidly developed a massive hemorrhagic myocardial infarct with spasms of the proximal coronary arteries. Repeated infusions of 15 mg/kg 5FU induced left ventricular hypertrophy, foci of myocardial necrosis, thickening of intra-myocardial arterioles, and disseminated apoptosis in myocardial cells of the epicardium, as well as endothelial cells of the distal coronary arteries. These results indicate that a spasm of the coronary arteries is not the only mechanism of 5FU cardiotoxicity, and that apoptosis of myocardial and endothelial cells can result in inflammatory lesions mimicking toxic myocarditis.

Myocardial ischemia affects mitochondrial function leading to ionic imbalance and susceptibility to ventricular fibrillation. Trimetazidine (TMZ), a metabolic agent, is clinically used as an anti-anginal therapy. This study was conducted to compare the effect of TMZ 20 mg immediate release (IR) and TMZ 35 mg modified release (MR), two bioequivalent marketed formulations of TMZ, on cardioprotection during acute ischemia in pigs. A 4-day oral treatment with TMZ 20 mg IR (800 mg, tid) or TMZ 35 mg MR (1,400 mg, bid) had no effect on ventricular fibrillation threshold (VFT) prior to ischemia but significantly prevented the decrease in VFT observed in placebo-treated groups after a 1-min left anterior descending coronary artery occlusion. This effect occurred without modifying cardiac hemodynamic and conduction parameters. In both TMZ-treated groups, a significant reduction of the ischemic area as well as a protection of cardiomyocytes were observed. Cardiac enzymatic activity (phosphorylase, succinate dehydrogenase, ATPase) was increased in TMZ-treated groups. Both formulations preserved mitochondrial structure and improved mitochondrial function as demonstrated by a twofold increase of oxidative phosphorylation, by a reduction of reactive oxygen species (ROS) production (>30 %) and by a trend to increase the mitochondrial calcium retention capacity. In this model of ischemia, both TMZ formulations, leading to equivalent TMZ plasma exposures, demonstrated similar cardioprotective effects. This protection could be attributed to a preservation of mitochondrial structure and function, which plays a central role in ATP and ROS production and consequently could be considered as a target of cardioprotection.

We present the case of a 50-year-old female with polyarthralgias and dysphonia. Indirect laryngoscopy revealed the presence of cricoarytenoid arthritis. The patient complained of dryness of the eyes and oral mucosa and was diagnosed with Sjögren's syndrome. Treatment with prednisolone quickly brought remission of systemic and laryngeal symptoms as well as improvement in the results of video-laryngostroboscopic tests. Laryngeal involvement is uncommon in Sjögren's syndrome. One case with vocal nodules, one with lymphocytic infiltration of the larynx, and one with repeated false cord swelling have been previously reported.

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A major risk associated with bupivacaine during myocardial ischemia is ventricular fibrillation. We investigated the influence of ropivacaine on cardiac contractility and the propensity to ventricular fibrillation before and after myocardial ischemia in a placebo-controlled pig study. Anesthetized domestic pigs were administered 1 mg.kg(-1) of ropivacaine intravenously over 1 min and then 0.03 mg.kg(-1).min(-1) as a 30-min infusion, or saline. The following endpoints were measured before and after ropivacaine administration: (1) the ventricular fibrillation threshold (VFT) before and during myocardial ischemia induced by total transient ligation of the anterior interventricular artery and (2) electrophysiological (sinus heart rate, duration of QRS and QT intervals) and hemodynamic (blood pressure, the time derivative of left ventricular pressure [peak LV dP/dt]) parameters. Ropivacaine induced no changes in sinus heart rate, QRS, and or QT before or during ischemia. In contrast, there was a mild increase in the VFT before ischemia, which was drastically and significantly reduced during ischemia. The reduction of peak LV dP/dt during ischemia was further increased by ropivacaine. We also found that the effect of ropivacaine on the VFT was coronary blood flow-dependent, with a markedly decreased threshold in the presence of ischemia. Similar effects have been observed in humans with several other local anesthetics, as well as with class I antiarrhythmic drugs. The results of this study should be taken into account by anesthesiologists when administering ropivacaine to coronary patients.