Y. Han et al., LEFT-VENTRICULAR PRESSURE TRANSMISSION TO MYOCARDIAL LYMPH VESSELS ISDIFFERENT DURING SYSTOLE AND DIASTOLE, Pflugers Archiv, 423(5-6), 1993, pp. 448-454
In six open-thorax-anaesthetized dogs with paced hearts and a retrogra
dely cannulated epicardial lymph vessel, the sensitivity of myocardial
lymph pressure to left ventricular pressure during systole and during
diastole was determined. The lymph vessels were cannulated using PE-9
0 tubing, and lymph pressure was measured by connecting the cannula to
, a microtip pressure transducer. To obtain the systolic sensitivity,
left ventricular pressure was changed by clamping the descending aorta
, which caused left ventricular pressure to increase. The diastolic se
nsitivity was obtained from natural variation to left ventricular pres
sure caused by atrial contractions during induced long diastoles. The
mean ratio of the pulse in lymph pressure to the pulse in left ventric
ular pressure was determined: systole: 0.069 +/- 0.013, n = 213, diast
ole: 0.76 +/- 0.16, n = 249 and, if possible, linear regression analys
is between lymph and left ventricular pressure was performed. The syst
olic regression coefficients could be determined in six dogs and the d
iastolic coefficients in three dogs. During long diastoles lymph press
ure variations are on average 76 per cent of those in the left ventric
le. However, during systole, the sensitivity of lymph pressure to left
ventricular pressure is more than ten times lower. It is not unlikely
that the structural embedment of lymph vessels within the myocardium
is such that volume variations by cardiac contraction are limited.