Catheterization studies of cardiac hemodynamics in normal pregnant women with reference to left ventricular work

Rose, David J.; Bader, Mortimer E.; Bader, Richard A.; Braunwald, Eugene

doi:10.1016/0002-9378(56)90107-7

Cited by 45 publications

(8 citation statements)

References 26 publications

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“…This was a result of the increased cardiac output and the lower systolic blood pressure. The results follow the expected trend (19,30) with TPR declining during the 25th week compared with the 15th week, then increasing during the 35th week. Conversely, as TPR declined, cardiac work increased.…”

Section: Discussionsupporting

confidence: 72%

“…This V02 was used to determine the appropriate pedal frequency for the water trial. The immersion trial occurred in a tank that contained 17,625 liters of water, was filtered, and the temperature controlled to 30.0 0 0.2 °C. The trial encompassed 20 mm of rest in the water immersed to the level of the xiphoid and 20 mm of exercise at the predetermined pedal frequency.…”

Section: Methodsmentioning

confidence: 99%

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Cardiovascular Responses of Pregnant Women During Aerobic Exercise in Water: A Longitudinal Study

McMurray

Katz²,

Berry³

et al. 1988

Int J Sports Med

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To determine the effects of pregnancy on the cardiovascular responses to immersion and exercise in water, 12 women completed 20 min of immersion and 20 min of bicycle ergometry at 60% predicted VO2max in 30 degrees C water during their 15th, 25th, and 35th week of pregnancy as well as 8-10 weeks post partum. Immersion lowered the resting heart rate approximately 8 bts/min (P less than 0.05). Exercise in water also resulted in a lower heart rate as compared with the same level of exercise on land (132 +/- 4 vs 149 +/- 6 bts/min; P less than 0.05). Both the rest and exercise heart rate responses were independent of duration of pregnancy or pregnancy status. Post partum exercise cardiac output averaged 9.9 +/- 0.4 l/min, significantly lower (P less than 0.05) than the 15th (12.7 +/- 0.5), 25th (14.7 +/- 0.5), or 35th week (15.1 +/- 0.7 l/min). Total peripheral resistance was greatest (P less than 0.05) post partum (657 +/- 29 dyn.s/cm5) compared with either the 15th (515 +/- 27), 25th (407 +/- 18), or 35th week (450 +/- 23). The results indicate that exercise in water lowers the heart rate compared with land exercise at the same metabolic rate. The combined effect of exercise, water, and pregnancy may elevate the cardiac output more than expected on land, but the same general pattern of exercise response will be evident throughout the duration of pregnancy. The results further suggest that water alters the heart rate and blood pressure responses such that land-derived exercise target heart rates should not be used to prescribe exercise intensity in water.

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Section: Discussionsupporting

confidence: 72%

Section: Methodsmentioning

confidence: 99%

Cardiovascular Responses of Pregnant Women During Aerobic Exercise in Water: A Longitudinal Study

McMurray

Katz²,

Berry³

et al. 1988

Int J Sports Med

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“…Afferent impulses originating in the stretch receptors of the left atrium (possibly the right) or in the other parts ofthe cardiothoracic vasculature and transmitted to the brain via the vagus nerves are primarily responsible for the control of AVP release in response to volume changes of a magnitude which do not affect mean arterial pressure (7,33,34). We are unaware of atrial, central venous, and/or pulmonary artery wedge pressure measurements in gravid rats but these values are unchanged in human pregnancy (35). Thus, there may be a primary vascular adaptation to the blood volume expansion (i.e., an increase in compliance) and since the increase is accommodated without increment in left atrial pressure, the central nervous system would interpret this new volume status as normal.…”

Section: Discussionmentioning

confidence: 99%

Role of volume in the regulation of vasopressin secretion during pregnancy in the rat.

Barron¹,

Stamoutsos²,

Lindheimer³

1984

J. Clin. Invest.

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A s bstract. We previously observed that osmoregulation and the osmotic threshold for antidiuretic hormone secretion were altered during pregnancy in SpragueDawley rats and the present study evaluated the influence of volume on arginine vasopressin (AVP) release during gestation in this species. Basal plasma osmolality (Posm) and intravascular volume were 297±3 mosmol/kg and 16.2±1.2 ml in virgin animals compared with 290±2 mosmol/kg and 20.2±2.3 ml in 14-d pregnant rats and 287±3 mosmol/kg and 25.2±2.3 ml in 21-d (near-term) pregnant rats (P < 0.001, each pregnant group vs. virgin). Isosmotic volume depletion was produced by intraperitoneal polyethylene glycol. Volume decreased from 1 to 26% and blood pressure remained stable during decrements as high as 16%. Plasma AVP (PAvp) did not rise significantly in either group ofpregnant animals or virgin controls until blood volume depletion reached 6-7%, after which levels rose in a similar exponential manner in virgin, 14-d, and 21 -d pregnant animals. In terms of absolute changes, however, PAvp in gravid rats started to increase when intravascular volume was still considerably greater than basal blood volume in the nonpregnant controls.Other experiments, where Posm was increased by intraperitoneal hypertonic saline, reconfirmed that the osmotic threshold for AVP secretion was reduced 10 mosmol/kg during pregnancy and that AVP release was stimulated by increments in body tonicity as small as 1-2%. In parallel studies, blood volume contraction and increases in Posm were evoked by intraperitoneal polyethylene glycol dissolved in hypertonic saline and results compared with animals receiving intraperitoneal saline alone. Decrements in volume (n7%), which alone would increase PAvp minimally, increased the sensitivity of the secretory response to changes in osmolality two-to threefold, an effect which was similar in virgin and gravid animals. Finally, restricting water intake of pregnant rats to that of virgins on days 16-20 of gestation led to suboptimal volume expansion, hypertonicity, and an exaggerated increase in PAVP.These results demonstrate that despite an intravascular space which at term is nearly twice that of virgin rats, pregnant animals secrete AVP in response to fractional volume depletion in a manner similar to nonpregnant controls; that is, the relationship between total blood volume and AVP secretion is altered during gestation such that the expanded blood volume is recognized as normal.

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“…22,23 As a result, resting VO 2 is progressively increased by16%to32%inpregnantwomen compared with the nonpregnant state. [24][25][26][27][28][29][30] Aerobic Capacity During Pregnancy At the start of exercise, energy expenditure (or oxygen uptake) increases in relation to the intensity, duration and type of exercise, and blood flow (carrying oxygen and nutrients) is redistributed to the working muscle. Submaximal exercise responses are especially affected by exercise modality.…”

Section: Energy Expenditure During Pregnancymentioning

confidence: 99%

Maternal Responses to Aerobic Exercise in Pregnancy

Davenport

Skow

Steinback

2016

Clinical Obstetrics &Amp; Gynecology

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Exercise is one of the most physiologically challenging stressors requiring the coordination of metabolic, respiratory, and cardiovascular responses to meet increased energy requirements of the working muscle. During pregnancy, all women without contraindication are encouraged to exercise as part of a healthy lifestyle. Pregnancy itself is associated with profound physiological adaptations to the maternal cardiovascular, respiratory, and metabolic systems, which serve to support the needs of the growing fetus. Therefore the physiological adaptations to exercise during pregnancy are more pronounced and critically important. This review provides an overview of our current understanding of the physiological adaptations to acute prenatal exercise.

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Catheterization studies of cardiac hemodynamics in normal pregnant women with reference to left ventricular work

Cited by 45 publications

References 26 publications

Cardiovascular Responses of Pregnant Women During Aerobic Exercise in Water: A Longitudinal Study

Cardiovascular Responses of Pregnant Women During Aerobic Exercise in Water: A Longitudinal Study

Role of volume in the regulation of vasopressin secretion during pregnancy in the rat.

Maternal Responses to Aerobic Exercise in Pregnancy

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