The more aggressive therapeutic approach with initial bypass surgery for patients with a single severe proximal stenosis of the left anterior descending coronary artery is associated with a lower incidence of medium-term adverse events than coronary angioplasty or medical treatment. However, all three strategies resulted in a similar incidence of death and infarction during an average follow-up period of 3 years. This information should be taken into consideration when physicians and patients make therapeutic choices in this setting.
BackgroundCardiac tumors are rare, mostly benign with high embolic potential.ObjectivesTo correlate the histological type of cardiac masses with their embolic potential,
implantation site and long term follow up in patients undergoing surgery.MethodsBetween January 1986 and December 2011, we retrospectively analyzed 185
consecutive patients who underwent excision of intracardiac mass (119 females,
mean age 48±20 years). In 145 patients, the left atrium was the origin site. 72%
were asymptomatic and prior embolization was often observed (19.8%). The diagnosis
was established by echocardiography, magnetic resonance and histological
examination.ResultsMost tumors were located in the left side of the heart. Myxoma was the most common
(72.6%), followed by fibromas (6.9%), thrombi (6.4%) and sarcomas (6.4%). Ranging
from 0.6cm to 15cm (mean 4.6 ± 2.5cm) 37 (19.8%) patients had prior embolization,
stroke 10.2%, coronary 4.8%, peripheral 4.3% 5.4% of hospital death, with a
predominance of malignant tumors (40% p < 0.0001). The histological type was a
predictor of mortality (rhabdomyomas and sarcomas p = 0.002) and embolic event
(sarcoma, lipoma and fibroelastoma p = 0.006), but not recurrence. Tumor size,
atrial fibrillation, cavity and valve impairment were not associated with the
embolic event. During follow-up (mean 80±63 months), there were 2 deaths (1.1%)
and two recurrences 1 and 11 years after the operation, to the same cavity.ConclusionMost tumors were located in the left side of the heart. The histological type was
predictor of death and preoperative embolic event, while the implantation site
carries no relation with mortality or to embolic event.
Prior transient episodes of ischemia ("ischemic preconditioning") reduce lactate accumulation and attenuate acidosis during a subsequent prolonged ischemic insult. The mechanisms responsible for attenuated glycolytic catabolite accumulation have not been established but may include earlier exhaustion of glycogen stores, slowed glycogenolysis before complete glycogen depletion, and/or inhibition of glycolysis. Simultaneous repeated measures of myocardial glycogen and the rates of glycolysis, glycogenolysis, glucose utilization, and glycolytic ATP production were obtained during total ischemia by 13C nuclear magnetic resonance spectroscopy in control and ischemia-preconditioned isolated rat hearts. Both [13C]glycolytic and [13C]glycogenolytic rates were significantly lower during total ischemia in preconditioned compared with control hearts (0.77 +/- 0.04 versus 1.06 +/- 0.06 mumol/min per gram wet weight [P < .01] for glycolysis and 0.15 +/- 0.07 versus 0.78 +/- 0.12 mumol/ min per gram wet weight [P < .001] for glycogenolysis, respectively, at 2.5 minutes of ischemia). Slowed glycolysis was present even during the early minutes of ischemia, when significant amounts of available [13C]glycogen were still present. Importantly, the reduction in the rate of glycogenolysis was larger and out of proportion to the reduction in glycolysis and occurred despite an increase in glucose utilization in preconditioned hearts (2.23 +/- 0.15 versus 1.5 +/- 0.10 mumol/min per gram wet weight at 1.25 minutes, P < .01). During early ischemia, conversion of glycogen phosphorylase to the a or "active" form was less in preconditioned than in control hearts (29.1 +/- 2.6% versus 41.2 +/- 9.8%, respectively; P < .05). Taken together, these findings demonstrate that ischemic preconditioning significantly depresses glycolytic catabolite accumulation during sustained ischemia not by more severe glycolytic inhibition or exhaustion of glycogen stores but by depressed glycogenolysis from the onset of ischemia.
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