Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Left ventricular pressure

The heart, a four-chambered muscular pump has as its primary purpose the propelling of blood throughout the cardiovascular system. The left ventricle is the principal pumping chamber and is therefore the largest of the four chambers in terms of muscle mass. The efficiency of the heart as a pump can be assessed by measuring cardiac output, left ventricular pressure, and the amount of work requHed to accomplish any requHed amount of pumping. [Pg.127]

Anaesthetized studies conducted using data capture systems to record six lead ECG (I, II, III, aV, and aVf), left ventricular pressure variables, arterial blood pressure and respiratory measurement of arterial blood flow in selected vascular beds, cardiac output and arterial blood gas measurement. ECG intervals are measured from the lead II ECG and Q-T interval can be corrected for heart rate using Bazett s, Friderecia s or Van De Water s formulas. [Pg.743]

Sato, K., Kandori, H., and Sato, S., Evaluation of a new method using telemetry for monitoring the left ventricular pressure in free-moving rats, ]. Pharmacol. Toxicol. Methods, 31, 191-198,1994. [Pg.283]

Several studies have indicated that n-butane sensitizes the myocardium to epinephrine-induced cardiac arrhythmias. In anesthetized dogs, 5000 ppm caused hemodynamic changes such as decreases in cardiac output, left ventricular pressure, and stroke volume, myocardial contractility, and aortic pressure. Exposure of dogs to 1-20% butane for periods of 2 minutes to 2 hours hypersen-... [Pg.97]

Fig. 11. Changes In gated NMR spectra during the cardiac cycle. Top panel isovolumic left ventricular pressure In a ferret heart paced at 0.99 Hz in 8 mM [Ca +]. NMR spectra were acquired at the two times indicated on the pressure record (a) 10 ms prior to stimulation (b) 75 ms after stimulation. Middle panel shows gated F NMR spectra (each from 800 acquisitions) recorded at (a) and (b), as indicated. The bound (B) and free (F) peaks of 5F-BAPTA exhibit distinct chemical shifts at approximately 8 and 2 ppm, respectively, downfield from a standard of 1 mM 6-Ftryptophan at 0 ppm. It appears that the free [Ca +] varied during the cardiac cycle. Bottom panel shows gated P spectra (400 scans) acquired at times a and b in the same heart. The major peaks correspond to phosphocreatine (0 ppm), ATP (the three peaks upfield from phosphocreatine), and inorganic phosphate (the small peak at 4-5 ppm) (Reproduced from Marban et al. Circ. Res. 1988 63 673-678 [311] with permission of Lippincott, Williams Wilkins). Fig. 11. Changes In gated NMR spectra during the cardiac cycle. Top panel isovolumic left ventricular pressure In a ferret heart paced at 0.99 Hz in 8 mM [Ca +]. NMR spectra were acquired at the two times indicated on the pressure record (a) 10 ms prior to stimulation (b) 75 ms after stimulation. Middle panel shows gated F NMR spectra (each from 800 acquisitions) recorded at (a) and (b), as indicated. The bound (B) and free (F) peaks of 5F-BAPTA exhibit distinct chemical shifts at approximately 8 and 2 ppm, respectively, downfield from a standard of 1 mM 6-Ftryptophan at 0 ppm. It appears that the free [Ca +] varied during the cardiac cycle. Bottom panel shows gated P spectra (400 scans) acquired at times a and b in the same heart. The major peaks correspond to phosphocreatine (0 ppm), ATP (the three peaks upfield from phosphocreatine), and inorganic phosphate (the small peak at 4-5 ppm) (Reproduced from Marban et al. Circ. Res. 1988 63 673-678 [311] with permission of Lippincott, Williams Wilkins).
It is relatively selective inhibitor of peak III cyclic AMP phosphodiesterase isoenzyme in cardiac and vascular muscle. In patients with CHF, it produces dose related and plasma concentration related increase in the maximum rate of increase of left ventricular pressure. Milrinone has a direct inotropic and direct arterial vasodilator activity. It is administrated by IV infusion 0.50 mg/kg over 10 min with a maximum daily dose of 1.13 mg/kg. [Pg.173]

Left ventricular pressure measurements are monitored continuously by use of a 5F end-hole pig-tail catheter in the left ventricular apex and a 6F femoral sheath in order to be able to assess the gradient, If the outflow gradient is absent or small under the basal conditions, the magnitude of provocable obstruction is most appropriately assessed with maneuvers (Valsalva, ventricular pacing, extrasystoles, physiological exercise, amyl nitrate), The inability to elicit any provocable gradient is a contraindication to the procedure,... [Pg.605]

The left ventricular pressure transducer is then implanted. The pericardium is opened so that the apex of the heart is exposed. The heart is gently held in one hand and two stitches in the ventricular wall for fixation are made. A purse-string suture is made around the apex. A sharp spike is then placed into the apex of the left ventricle and the transducer is placed into the ventricle and sutured firmly in place. [Pg.66]

The hemodynamic and ECG parameters include systolic, diastolic and mean aortic pressure, peak systolic and end-diastolic left ventricular pressure, LV dP/dt max and dP/dt min, heart rate PQ-, QRS- and QT intervals. NOTOCORD-software (or equivalent) is used for acquisition of data whereas EXCEL (or equivalent) is used for data analysis. Data are summarized at predefined time points by calculating median values+ SD. Whereas all physiological parameters are routinely averaged over predefined time intervals, it has been proposed that for the ECG only a few beats... [Pg.66]

The amplified MAP signals together with systemic blood pressure, left ventricular pressure, heart rate and ECG are continuously monitored using a polygraph system. Each value of ECG and MAP should represent the mean of at least three consecutive complexes. [Pg.70]

Bames GE, Horwith LD, Bishop VS (1979) Reliability of the maximum derivatives of left ventricular pressure and internal diameter as indices of the inotropic state of the depressed myocardium. Cardiovasc Res 13 652-662 Bishop VS, Horwitz LD (1971) Effects of altered autonomic control on left ventricular function in conscious dogs. Am J Physiol 221 1278-1282... [Pg.91]

Fiedler VB, Oswald S, Gobel H, Faber W, Scholtholt J (1980) Determination of left ventricular dimensions with ultrasound. J Pharmacol Methods 3 201-219 Horwitz LD, Bishop VS (1972) Left ventricular pressure-dimension relationships in the conscious dog. Cardiovasc Res 6 163-171... [Pg.91]

Left ventricular pressure (LVP) (mm Hg) is determined by inserting a microtip-catheter via the carotid artery retrogradely. [Pg.279]

PURPOSE AND RATIONALE Measurement of cardiac function and morphology is a key part of the preclinical evaluation of experimental medicinal compounds. Blood pressure, heart rate, and electrocardiogram evaluation are part of the core portfolio of safety pharmacology studies carried out in conscious telemetry dogs. If results from the core battery of tests raise concern then supplemental studies are conducted to measure endpoints such as left ventricular pressure, pulmonary arterial pressure, heart rate variability, baroreflex, cardiac output, ventricular contractility and vascular resistance. However, many... [Pg.388]

Alternatives to MRI include echo cardiography to measure LV wall thickness, lumen volume and cardiac output (Coatney 2001 Collins et al. 2003 de Simone et al. 1990 Zhou et al. 2004), dye-dilution techniques such as bolus thermodilution to measure cardiac output (Siren et al. 1990), and implanted pressure transducers and flow probes to measure left ventricular pressure... [Pg.390]

Langendorff-perfused rat heart have been investigated and compared to that of nifedipine. Nifedipine decreased concentration-dependent (IC50 = 8.89 1.09 x 10-8 M) left ventricular pressure leaving unaltered coronary perfusion pressure, whereas DP7 did not affect these parameters. Nifedipine did not modify QRS and QT intervals of ECG [112], It has also been investigated that neither pyruvate kinase nor lactate dehydrogenase was inhibited by DP7... [Pg.230]

Ishizaka S, Sievers RE, Zhu BQ, et al. New technique for measurement of left ventricular pressure in conscious mice. Am J Physiol Heart Circ Physiol 2004 286 H1208-H1215. [Pg.237]

Fig. 3. a1A-AR overexpression induces enhanced contractility but not cardiac hypertrophy. (A) Representative left ventricular pressure (LVP) and dP/dT tracings from transgenic animals (TG) and nontransgenic littermates (NTL). A slower recording speed is shown at the beginning. (B) In vivo effects of ISO administration before and after complete P-AR blockade with propanolol (left panel) in NTL (open square) and TG (closed square) mice. Effects of selective a1A-AR blocker KMD3213 on +dP/dT and -dP/ dT are shown in the right panel. (From ref. 29 2001 Lippincott Williams Wilkins.)... [Pg.301]

The effects of berbamine of the isolated and perfused working heart of the guinea pig was studied. The alkaloid was observed to depress the function of the isolated working heart in a dose-dependent manner. The alkaloid (3 mol/l) decreased the left ventricular pressure, aortic pressure -dP/dtmax, aortic blood flow and coronary blood flow, and increased left ventricular end-diastolic pressure. At a concentration of 100 mol/l, ventricular asystole was produced, but there was no influence on atrial contraction. Berbamine was also observed to antagonize epinephrine-induced arrhythmias [202]. [Pg.125]

Figure 5. A, Schematic of a Largerdortf perfused rat heart model. Retrograde perfusion is established through the aorta. Perfusate oxygenated with 95% O, and 5% CO, is circulated by a peristaltic pump and the flow can be adjusted. Left ventricular pressure is monitored Ihrough a balloon which is inserted into the empty left ventricle. Heart rhythm is controlled by pacing. Figure 5. A, Schematic of a Largerdortf perfused rat heart model. Retrograde perfusion is established through the aorta. Perfusate oxygenated with 95% O, and 5% CO, is circulated by a peristaltic pump and the flow can be adjusted. Left ventricular pressure is monitored Ihrough a balloon which is inserted into the empty left ventricle. Heart rhythm is controlled by pacing.
B. Recording of left ventricular developed pressure (LVDP is defined as ihe difference between systolic and diastolic left ventricular pressure) from Langcndorff perfused heart after stabilization followed by complete flow cessation (zero-flow global ischemia) and flow re-establishment (reperfusion). Note the development of isctiemic contracture (black arrow) and hypcrcontracturc early at the time of reperfusion (white arrow). [Pg.26]

C. Left ventricular pressure recording of a perfused rat heart model of zero-flow global ischemia and reperfusion. A progressive increase in LVDP occurs at reperfusion. This corresponds to myocardial stunning (data from our laboratory). [Pg.26]

The cardioprotective effect of EPO has also been demonstrated in animal models. EPO administration at the time of reperfusion significantly reduced infarct size and apoptosis (assessed by TUNEL staining) in a rabbit model of acute coronary occlusion and reperfusion.36 This effect was accompanied by increased activation of ERK and Akt in the unstressed myocardium.36 Similarly, EPO administration throughout the period of low-flow ischemia reduced apoptosis and improved recovery of left ventricular pressure in perfused rat hearts.34... [Pg.81]

Figure 3. Lcll ventricular pressure recordings obtained from isolated rat hearts subjected to zero-flow global ischemia and reperfusion. Ischemic contracture is exacerbated in thyroxine treated hearts (13) and is suppressed in the hypothyroid hearts (C) as compared to normal hearts (A). Recovery of left ventricular developed pressure is increased in both hypothyroid and hyperthyroid as compared to normal hearts. LVDP is defined as the difference between systolic and diastolic left ventricular pressure (data from our laboratory). Figure 3. Lcll ventricular pressure recordings obtained from isolated rat hearts subjected to zero-flow global ischemia and reperfusion. Ischemic contracture is exacerbated in thyroxine treated hearts (13) and is suppressed in the hypothyroid hearts (C) as compared to normal hearts (A). Recovery of left ventricular developed pressure is increased in both hypothyroid and hyperthyroid as compared to normal hearts. LVDP is defined as the difference between systolic and diastolic left ventricular pressure (data from our laboratory).
Friedel-Craft acetylation of385 followed by bromination yields 5-(2-bromoacetyl)-1,3-dibenzyl-1H, 3H-2,1,3,-benzothiadiazole-2,2-dioxide (387). Reaction of 387 with N-benzylated amines followed by reduction with hydrogen produces (388). No significant increase in heart rate, blood pressure, left ventricular pressure and bronchodilator activity was observed when the thiadiazoles 388 were tested in dogs. [Pg.1013]

Not only do endocannabinoids affect vascular function, but they may also have direct cardiac actions. Ford et al. (2002) reported in the rat isolated heart that anandamide had a negative inotropic effect and reduced left ventricular pressure. This action appeared to be due to action at a novel cannabinoid receptor. In human atrial muscle, anandamide has also been shown to exert negative inotropic effects but, in this case, via the activation of CB, receptors (Bonz et al., 2003). [Pg.425]

Suga, H. 1971. Left ventricular pressure-volume ratio in systole as an index of chronic complete heart block in dogs. Jpn. Heart J. 12 153-160. [Pg.151]

EW is also termed stroke work and is represented as the area encircled by the left ventricular pressure-volume (P-V) diagram during each heart beat. The external mechanical work generated by the heart per unit body or heart weight is constant for mammalian species [Li, 1983a, b], that is. [Pg.279]

FIGURE 54.4 Left ventricular pressure, aortic pressure, and left ventricular volume during a single cardiac cycle showing the times of mitral valve closure (MVC), aortic valve opening (AVO), aortic valve closure (AVC) and mitral valve opening (MVO). [Pg.940]

FIGURE 54.5 Schematic diagram of left ventricular pressure-volume loops (a) End-systolic pressure-volume relation (ESPVR), end-diastolic pressure-volume relation (EDPVR) and stroke work. The three P-V loops show the effects of changes in preload and afterload, (b) Time-varying elastance approximation of ventricular pump function (see text). [Pg.942]

Pirzada, F.A., Ekong, E.A., Vokonas, P.S. et al, Experimental myocardial infarction Xlll. Sequential changes in left ventricular pressure-length relationships in the acute phase, Circulation, 53, 970-975,1976. [Pg.958]


See other pages where Left ventricular pressure is mentioned: [Pg.254]    [Pg.405]    [Pg.102]    [Pg.606]    [Pg.63]    [Pg.65]    [Pg.68]    [Pg.85]    [Pg.89]    [Pg.91]    [Pg.54]    [Pg.82]    [Pg.358]    [Pg.70]    [Pg.258]    [Pg.941]    [Pg.968]    [Pg.968]    [Pg.241]   
See also in sourсe #XX -- [ Pg.66 , Pg.68 ]




SEARCH



LEFT

Left ventricular

Left ventricular end-diastolic pressure

Ventricular

© 2024 chempedia.info