Chronic Performance of a New 4 Fr Left Ventricular Unipolar Lead in the Canine Model

2006 ◽  
Vol 12 (6) ◽  
pp. S67
Author(s):  
Vivek K. Sharma ◽  
Christine Palma ◽  
Peter Fong ◽  
Corey Brown
1990 ◽  
Vol 258 (3) ◽  
pp. H625-H633 ◽  
Author(s):  
T. J. Stahl ◽  
P. B. Alden ◽  
W. S. Ring ◽  
R. C. Madoff ◽  
F. B. Cerra

A chronic canine model of hyperdynamic sepsis was achieved by cecal ligation and puncture (SEP) in conjunction with continuous high-volume fluid resuscitation. Cardiac function was evaluated using ultrasonic cardiac crystals placed across the major, minor, and wall thickness axes of the left ventricle, together with simultaneous arterial and ventricular pressure measurement. Seven to 10 days after crystal implantation, animals were randomized to either SEP (n = 10) or sham laparotomy control (n = 7). SEP dogs became febrile and lethargic, with elevated leukocyte counts and positive blood cultures for enteric organisms. They were also hyperdynamic, with significant increases in heart rate and cardiac output and a fall in systemic vascular resistance. Systolic blood pressure, stroke volume, and ejection fraction remained stable. Relative to control, the SEP group demonstrated a significant reduction in intrinsic contractility during systole, as measured by the heart rate and load-independent index of left ventricular performance Emax (P less than 0.01), confirming the observations of others. In addition, however, diastolic function also became markedly abnormal with a progressive increase in unstressed and end-diastolic ventricular volumes (P less than 0.05) and a significant decrease in myocardial compliance as quantitated by transmural pressure vs. volume-strain analysis. It is hypothesized that this increase in diastolic volume helps to maintain global cardiac performance during the hyperdynamic response to sepsis in the presence of adequate volume support.


2009 ◽  
Vol 297 (2) ◽  
pp. H708-H717 ◽  
Author(s):  
Isaac George ◽  
Brad Morrow ◽  
Kai Xu ◽  
Geng-Hua Yi ◽  
Jeffrey Holmes ◽  
...  

B-type natriuretic peptide (BNP) is an established first-line therapy for acute decompensated heart failure (HF), but its efficacy in preventing left ventricular (LV) remodeling after myocardial injury is unknown. The goal of this study was to evaluate the effects of BNP therapy on remodeling after ischemic injury in an awake canine model. Dogs were chronically instrumented for hemodynamics. Ischemia was created by daily coronary embolization (Embo; 3.1 × 104 beads/day) for 3 wk; 60 min after the first embolization, BNP (100 ng·kg−1·min−1; n = 6) or saline (control; n = 6) was continuously infused via a left atrial catheter for 3 wk. Hemodynamics and echocardiography were performed in an awake state at baseline, 3 wk after Embo + BNP infusion, and 4 wk after stopping Embo + BNP infusion. End-systolic elastance (Ees) and LV change in pressure over time (dP/d t) were preserved throughout Embo + BNP therapy versus control therapy (Ees: 3.76 ± 1.01 vs. 1.41 ± 0.16 mmHg/ml; LV dP/d t: 2,417 ± 96 vs. 2,068 ± 95 mmHg/s; both P < 0.05 vs. control). LV end-diastolic dimension was significantly smaller in BNP-treated dogs compared with control dogs (4.29 ± 0.10 vs. 4.77 ± 0.17 cm), and ejection fraction was maintained in treated dogs vs. control dogs (53 ± 1% vs. 46 ± 2%) (both P < 0.05 vs. control). Cyclooxygenase (COX)-2 expression in terminal LV tissue was significantly reduced after BNP therapy. Treatment with continuous infusion of BNP preserved LV geometry, improved systolic function, and prevented the progression of systolic HF after persistent ischemic injury.


1985 ◽  
Vol 59 (3) ◽  
pp. 1019-1025 ◽  
Author(s):  
M. B. Maron

The purpose of this study was to evaluate the usefulness of the intracisternal administration of veratrine as a model of neurogenic pulmonary edema (NPE) in the alpha-chloralose-anesthetized dog. Veratrine (40–60 micrograms/kg) was injected into the cisterna magna of 17 animals, and systemic arterial, pulmonary arterial, and left ventricular end-diastolic (LVEDP) pressures were followed for 1 h. Eleven animals developed alveolar edema. In these animals, systemic arterial pressure increased to 273 +/- 9 (SE) Torr, pulmonary arterial pressure to 74.5 +/- 4.9 Torr, and LVEDP to 42.8 +/- 4.5 Torr, and large amounts of pink frothy fluid, with protein concentrations ranging from 48 to 93% of plasma, appeared in the airways. Postmortem extravascular lung water content (Qwl/dQl) averaged 7.30 +/- 0.46 g H2O/g dry lung wt. Six animals escaped developing this massive degree of edema after veratrine (Qwl/dQl = 4.45 +/- 0.24). These animals exhibited similar elevated systemic arterial pressures (268 +/- 15 Torr), but did not develop the degree of pulmonary hypertension (pulmonary arterial pressure = 52.5 +/- 6.7 Torr, LVEDP = 24.8 +/- 4.0 Torr) observed in the other group. These results suggest that both hemodynamic and permeability mechanisms may play a role in the development of this form of edema and that veratrine administration may provide a useful model of NPE.


1998 ◽  
Vol 65 (3) ◽  
pp. 663-666 ◽  
Author(s):  
Yasuhiro Uozaki ◽  
Arata Murakami ◽  
Hidetsugu Asanoi ◽  
Shinji Ishizaka ◽  
Takuro Misaki

Sign in / Sign up

Export Citation Format

Share Document