Ventricular dynamics

Vatner, S., Higgins, CB, Milland, RW, and Franklin, D. 1972. Direct and reflex effects of nitroglycerin on coronary and left ventricular dynamics in conscious dogs. J Clin Invest 51 2872-82. 

Grossman W, Braunwald E, Mann T, McLaurin LP, Green LH (1977) Contractile state of the left ventricle in man as evaluated from end-systolic pressure-volume relations. Circulation 56 845-852 Hunter WC, Janicki JS, Weber KT, Noordergraaf A (1979) Flow-pulse response A new method for the characterization of ventricular mechanics. Am J Physiol 237 H282-H292 Janicki JS, Reeves RC, Weber KT, Donald TC, Walker AA (1974) Application of a pressure servo system developed to study ventricular dynamics. J Appl Physiol 37 736-741 Mehmel HC, Stockins B, Ruffman K, Olshausen K, Schuler G, Kubler W (1981) The linearity of the end-systolic pressure-volume relation in man and its sensitivity for the assessment of left ventricular function. Circulation 63 1216-1222... 

ANS No, we are not simply talking about details of fitting data. Resistance is significant and must be accounted for when mathematically describing ventricular dynamics throughout systole as opposed to one instant in systole such as the end of systole, where flow is essentially zero. Moreover, as I indicated earlier, our resistance appears to have physical significance in that it represents some fundamental rate limiting process of the contractile machinery. 

Some of the applicable muscle models include the Maxwell, Voigt, Hill and Carlson models (Figure 1). In particular, the Carlson (1957) equation is used in much of this work to describe the stress-velocity relationship of cardiac muscle over the entire cardiac cycle. Min et al. (1978) found very little difference in analyzing ventricular dynamics when he alternately used Carlson s equation only during isotonic contraction and Hill s equation during isovolumic contraction. 

There are many models that have been used to describe ventricular dynamics. One of the most popular is the description of the left ventricle as a time varying hydraulic capacitor as proposed by Suga and Sagawa (1974). This paper will... 

Introduction Left Ventricular Dynamics Predictive Power ... 

Ongoing work is devoted to the accurate description of the origin and spread of excitation from the natural pacemaker to the rest of the heart. Computations of ventricular pressure development are being extended to account for blood flow dynamics in adjacent blood vessels. The thorax... 

Amiodarone (Cordarone, Pacerone) [Ventricular Antiarrhythmic/Adrenergic Blocker] Uses RecumMit VF or hemo-dynamically unstable VT, supraventricular arrhythmias, AF Action Class III antiarrhythmic (Table VI-7) Dose Adul. Ventricular arrhythmias IV 15 mg/min... 

Hypertrophic cardiomyopathy a primary myocardial disorder of sacromeric proteins with an autosomal dominant pattern of inheritance is characterized by asymmetric hypertrophy of the septum with or without dynamic obstruction of the outflow tract (1,2), The prevalence in the general population is estimated as 1 500 and it is the most common monogenic cardiac disorder, Annual mortality in an unselected population is reported to be about I % to 2%, and sudden death is the most common cause, Sudden death is assumed to be due to idiopathic ventricular arrhythmias, but hemodynamic factors and myocardial ischemia may be involved as well. 

Zeidan, A., Javadov, S., and Karmazyn, M. 2006. Essential role of Rho/ROCK-dependent processes and actin dynamics in mediating leptin-induced hypertrophy in rat neonatal ventricular myocytes. Cardiovasc. Res. 72 101-111. 

Roldan FJ, Vargas-Barron J, Espinola-Zavaleta N, Keirns C, Romero-Cardenas A. Severe dynamic obstruction of the left ventricular outflow tract induced by dobutamine. Echocardiography 2000 17(1) 37 0. 

Lande G, Maison-Blanche P, Fayn J, Ghadanfar M, Coumel P, Funck-Brentano C. Dynamic analysis of dofeti-lide-induced changes in ventricular repolarization. Clin Pharmacol Ther 1998 64(3) 312-21. 

The ECG pattern of subepicardial ischaemia -flattened or negative T wave - is observed in IHD (Table 2.1), but it may also appear in other situations (see Table 3.2). We have to remember that the ECG pattern of subepicardial ischaemia (negative T wave) although may probably be due to real active ischaemia (ACS), more often appear in the dynamic changes of some ACS as a reperfusion pattern or is explained by the changes that MI has induced in ventricular repolarisation (chronic Q-wave MI) (p. 37 and Table 8.1). 

---