Rodríguez Ja

Endocarditis infecciosa: análisis de 261 casos y resultados del tratamiento con un enfoque multidisciplinario

Background: Early diagnosis, an effective treatment and prompt recognition of complications are essential to improve the prognosis of infective endocarditis (IE) Aim: To report the results of a multidisciplinary approach to diagnosis and management of patients with IE at the Universidad Catolica de Chile Hospital. Patients and methods: The clinical history, diagnosis, treatment and outcome of 261 episodes (Duke criteria) of IE admitted between January 1980 and January 1999 were analyzed. These included 185 episodes of native, 73 of prosthetic valve and 3 of nonvalvular IE. Results: Sixty nine percent of patients were men and the mean age was 49 ± 16 years. Seventy five percent had a definite diagnosis of IE (Duke). S. viridans, staphylococci and enterococci together constituted 85% of the isolated bacterial strains. Twenty seven had culture-negative IE, related to a high incidence of antibiotic therapy prior to diagnosis. Transesophageal echocardiography was performed in 102 cases and it detected vegetations in 91% of aortic and 96% of mitral IE, rupture or prosthesis dehiscence in 67% of aortic and 52% of mitral IE and abscesses in 51% of aortic and 15% of mitral IE. Fifty one percent developed heart failure and 34% had embolic events. S. aureus IE was associated to a higher incidence of embolic events, complications which contraindicated surgery and increased mortality rate (27%). Of all patients, 40% were treated exclusively with antibiotics, 52% were operated on and 8% had surgical indication but were nonoperable because of serious complications. The overall mortality was 16.3%: 13% in the medical, 9% in the surgical and 81% in the non-operable groups. The type of treatment and mortality rates did not differ between IE of native valves and prosthetic valves. Long term follow up showed survival rates of 73% at 5 years and 66% at 10 years. Conclusion: A multidisciplinary approach may be very helpful to improve the prognosis of IE. (Rev Med Chile 2000; 128: 708-20).

Effect of Acute Isovolemic Anemia on Cardiac Output and Estimated Hepatic Blood Flow in the Conscious Dog

The effect of acute isovolemic anemia induced by Dextran 70 exchange (40 ml/kg body weight) on estimated hepatic blood flow, cardiac output, and related variables was studied in 27 experiments on 24 unsedated dogs. Experiments were performed 5–10 days after implantation of an electromagnetic flow transducer around the aorta and catheters in the hepatic vein, jugular vein, and carotid artery. Bromsulphalein infusion was used to measure estimated hepatic blood flows, and electromagnetic measurements of stroke volume and cardiac output were calibrated using a simultaneous dye-dilution curve. With a mean fall in hematocrit from 34.8 to 17.0 ml/100 ml, estimated hepatic blood flow rose from 53.6 ± 15.3 (SD) to 76.3 ± 21.1 ml/min kg−1 and splanchnic vascular resistance fell from 119 ± 41 to 93 ± 38 mm Hg/liter min−1 (P<0.01). These changes were proportionately smaller than the increase in cardiac output (182 ± 80 to 350 ± 146 ml/min kg−1) and the fall in systemic vascular resistance (37.0 ± 4.9 to 21.7 ± 4.9 mm Hg/liter min−1), leading to a fall in the ratio of estimated hepatic blood flow to cardiac output from 34.3 to 25.7%. Bromsulphalein extraction ratio was significantly decreased, but Bromsulphalein clearance increased 44%. Splanchnic oxygen consumption did not change. β-receptor blockade in 6 dogs (propranolol 0.5 mg/kg body weight) failed to prevent or attenuate the increase in estimated hepatic blood flow or cardiac output when the blocking agent was given before induction of acute isovolemic anemia. Sixty minutes after accomplishment of anemia, estimated hepatic blood flow and cardiac output had returned toward but not to control levels. Induction of β-receptor blockade in the anemic dog did not influence the effects of time on estimated hepatic blood flow or cardiac output. We concluded that acute isovolemic anemia leads to a significant increase in estimated hepatic blood flow that is essentially independent of β-receptor stimulation.

Experiencia de 36 años con marcapasos implantables: Un análisis histórico

Background: The implantation of pacemakers improves cardiac function and quality of life, in particular with dual chamber DDD and DDDR modes. Aim: To evaluate our clinical experience and results on pacemaker implantation, from 1963 to 1998. Material and methods: Computerized data collected from 2,445 consecutive paced patients was reviewed. A total of 3,554 operative procedures were performed, including 412 procedures for complications and 697 pacemaker replacement. Patient survival was determined from clinical records, inquiry to pacemaker manufacturers and death certificates from Servicio de Registro Civil e Identificacion de Chile (Chilean Civil and Identification Registry). Results: Use of dual chamber (DDD and DDDR) pacemakers increased progressively up to 74% from 1988 to 1998. Complication rate was 42% in the 1963-1976 study period, it decreased to 10.6% in the 1977-1987 study period, and to 5.6% by 1988-1998. Only two patients died during surgery in the study period (0.08%). In the 1977-1987 period, pacemakers lasted 10.6 years. Survival rates were 52% at ten years, 33% at 15 years, and 21% at 20 years, with a median survival of 11.7 years, and 7.24 years in patients over 80 years old. Conclusions: Transvenous permanent pacing can be accomplished today with a low complication rate, mainly due to better technology and surgical procedures (Rev Med Chile 2002; 130: 132-42)