With a view of possible reduction in antibiotic dosage, several prospective randomized comparative trials performed in our institution showed that a 4-day prophylactic antimicrobial regimen with cefazolin was equally effective as a 2-day prophylaxis with cefuroxime and that the best regimen was equally as effective as a double dose of ceftriaxone prophylaxis in major cardiovascular surgery. In this prospective randomized comparative study, 1-day cefazolin prophylaxis (4 X 0.5 g intravenously) was compared with a single dose of ceftriaxone prophylaxis (2 g intravenously). Of the 900 patients enrolled in the study, 17 were subsequently excluded. Of the remaining 883 patients, 439 were in the cefazolin group and 444 were in the ceftriaxone group. The overall postoperative infection rate was 5.0% in the cefazolin group and 4.5% in the ceftriaxone group. In view of the almost identical infection rates in both groups, we considered that a single 2 g dose of ceftriaxone offers patients a reliable antimicrobial prophylaxis. The single-dose prophylaxis has the additional advantage of reducing the dosage administered and the costs of administration.

Bacterial Infections↗

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Late systolic stress-diameter relation in patients with aortic valve disease before and after valve replacement.

The end-systolic pressure-diameter ratio (Ees) and the maximal pressure-diameter ratio (Emax) during systolic ejection were determined in 10 control patients and 25 patients with aortic valve disease before and 18 months after successful valve replacement. The pressure-diameter ratio was determined from simultaneous M-mode echocardiograms and high-fidelity pressure measurements. A new index of myocardial contractility, as proposed by Pouleur and co-workers, was assessed from the late systolic stress-diameter relationship during one single heart cycle. The slope of this stress-diameter relationship was used for determination of myocardial contractility. Meridional wall stress was calculated from echo-pressure measurements at time intervals of 5 to 10 msec. The aortic valve patients were divided into two groups according to the preoperative angiographic ejection fraction: group 1 (ejection fraction greater than or equal to 57%) consisted of 16 patients and group 2 (ejection fraction less than 57%) of 9 patients. Standard hemodynamics showed a significant decrease in left ventricular end-diastolic pressure from 18 to 11 mm Hg in group 1 (P less than 0.01) and from 16 to 12 mm Hg (NS) in group 2. Peak systolic pressure decreased from 186 to 135 mm Hg (P less than 0.01) in group 1 and from 155 to 140 mm Hg (NS) in group 2. Left ventricular end-diastolic volume decreased from 137 to 105 ml/m2 in group 1 and from 225 to 150 ml/m2 in group 2 (P less than 0.05) whereas left ventricular ejection fraction remained unchanged in group 1 (67 versus 65%) and increased slightly in group 2 (45 versus 51%) following surgery. Emax and Ees were preoperatively significantly decreased in group 2 when compared to group 1. Postoperatively, Emax and Ees were no longer significantly different between the two groups although left ventricular ejection fraction remained significantly depressed in group 2 after surgery when compared to group 1. The slope of the late systolic stress-diameter relationship (beta) and the diameter at zero stress (D0) did not show any difference between the two groups pre- as well as postoperatively. Thus it is concluded that Ees and Emax might help to identify myocardial dysfunction in preoperative patients with aortic valve disease. However, in the presence of persistent myocardial dysfunction, as evaluated from systolic ejection fraction, following successful valve replacement, both Ees and Emax do not allow to identify patients with postoperative depressed myocardial function.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMedDate not supplied

Effects of chronic paired pacing upon left ventricular dynamices in the dog.

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Animals↗

PubMedDate not supplied

Cardiac surgery for Kartagener syndrome.

Two patients (one girl, one boy) with Kartagener syndrome (situs inversus, bronchiectasis, sinusitis), despite pulmonary problems and associated congenital cardiac anomalies, were operated on at the ages of 4 years and 7 years, respectively. They had had previous palliative treatment at the age of 3 months and 1.3 years, respectively. Both postoperative periods after total correction were without significant complications. Long-term follow-up was available for 9 and 19 years, respectively, with no manifestations of heart insufficiency. Both patients are physically active, and neither requires cardiac medication. Patients with Kartagener syndrome and associated congenital cardiac anomalies can successfully undergo multiple cardiac operations with good long-term outcome.

Cardiac Surgical Procedures↗

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Coagulation patterns during deheparinization with immobilized polycation.

Reversal of systemic heparinization with protamine is problematic during perfusion with heparin surface coated devices because protamine reacts with both circulating and surface bound heparin. Hence, the development of a deheparinization device allowing for ex vivo heparin absorption by the means of an immobilized polycation is of prime interest for a number of indications. To assess the coagulation patterns during ex vivo deheparinization, a heparin surface coated venovenous pump loop including a plasma separator with immobilized polycation was studied in a bovine model (n = 6, body weight 71 +/- 5 kg). After systemic heparinization with 300 IU of heparin/kg body weight, spontaneous evolution (control) of coagulation parameters was compared to ex vivo deheparinization with a mean pump flow of 500 ml/min. No device failure occurred during the procedures and all plasma separators remained patent. These baseline levels were measured for control versus ex vivo deheparinization: activated coagulation time 158 +/- 6 sec (161 +/- 4 sec: NS), antithrombin III 101 +/- 5% (108 +/- 8%: NS), fibrinopeptide A 3.4 +/- 1.7 ng/ml (4 +/- 1.7 ng/ml: NS). After heparin application mean activated coagulation time was longer than 1000 sec in both groups. Sixty minutes later, the activated coagulation time was 757 +/- 43 sec (184 +/- 5 sec: P < 0.05), antithrombin III was 96 +/- 12% (99 +/- 2%: NS), and fibrinopeptide A was 2.7 +/- 0.7 ng/ml (9.5 +/- 3.5 ng/ml: P < 0.05). It is concluded that ex vivo deheparinization resulted in significant acceleration of activated coagulation time normalization. Fibrinopeptide A production in the group with ex vivo deheparinization appeared to be higher. As antithrombin III levels were close to normal in both groups, allowing for adequate function of circulating as well as surface bound heparin, and the coagulation process was blocked by significant heparin levels in the control group, the difference for FPA may be due to activation of the coagulation process in the surgical field (sternotomy).

Animals↗

PubMedDate not supplied

Scaffold precoating with human autologous extracellular matrix for improved cell attachment in cardiovascular tissue engineering.

Cell attachment to a scaffold is a precondition for the development of bioengineered valves and vascular substitutes. This attachment is generally facilitated by the use of precoating factors, but some can cause toxic or immunologic side effects. Autologous extracellular matrix (ECM) is used as a precoating factor in our study. Ascending aortic tissue was cultured to obtain human myofibroblasts. Autologous ECM was extracted from the same aortic tissue. Poly(glycolic acid) (PGA) scaffolds were precoated with autologous ECM, human serum, or poly-L-lysine; the control group was pretreated with phosphate buffered saline (PBS). Myofibroblasts were seeded onto each scaffold, and the cell attachment was assayed and compared. Compared with the control group, precoating with human serum, poly-L-lysine, and ECM increased number of attached cells by 24%, 53%, and 48%, respectively. Differences between precoating groups were significant (p < 0.01), except for ECM versus poly-L-lysine. Scanning electron microscopy also demonstrated the high degree of cell attachment to the PGA fibers on scaffolds precoated with ECM and poly-L-lysine. Precoating polymeric scaffold with autologous human extracellular matrix is a very effective method of improving cell attachment in cardiovascular tissue engineering without the potential risk of immunologic reactions.

Aorta↗