Interaction between respiration and right versus left ventricular volumes at rest and during exercise: a real-time cardiac magnetic resonance study
Interaction between respiration and right versus left ventricular volumes at rest and during exercise: a real-time cardiac magnetic resonance study
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DOI：
10.1152/ajpheart.00752.2013
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发表时间：
2014-03-01
影响因子：
4.8
通讯作者：
Heidbuchel, Hein
中科院分区：
文献类型：
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作者：
Claessen, Guido;Claus, Piet;Heidbuchel, Hein
呼吸引起的胸内压力变化会影响左心室（LV）和右心室（RV）容积，其确切性质和程度此前尚未在人类中进行过评估。我们试图使用新颖的实时心脏磁共振（CMR）成像来检查这种“呼吸泵”。八名健康受试者在正常呼吸、屏气和 Valsalva 动作期间接受了连续多层实时 CMR。随后，由 9 名受试者组成的单独队列在休息时和增量运动期间接受了实时 CMR。在吸气和呼气峰值时测定 LV 和 RV 舒张末期容积 (EDV) 和收缩末期容积 (ESV) 以及舒张期和收缩期偏心率指数。正常呼吸期间，吸气导致 RV 容量增加 [RVEDV：+18 +/- 8%，RVESV：+14 +/- 12%，RV 每搏输出量 (SV)：+21 +/- 10%，P < 0.01]，而 LV 容量相反减少（交互作用 P < 0.0001）。吸气末屏气期间，RV SV 下降 9 +/- 10% (P = 0.046)，而 LV SV 没有变化。在瓦尔萨尔瓦动作期间，双心室容量减少（RVEDV：-29 +/- 11%，RVESV：-16 +/- 14%，RV SV：-36 +/- 14%，LVEDV：-22 +/- 17%，LV SV：-25 +/- 17%，P < 0.01）。在整个运动过程中，呼吸对左心室和右心室容量的相互影响得以维持。无论是休息时还是运动时，吸气时的舒张期和收缩期偏心指数均大于呼气时的舒张期和收缩期偏心率指数（两者均 P < 0.0001）。总之，心室容积随呼吸阶段振荡，使得 RV 和 LV 容积分别在吸气峰值和呼气峰值时达到最大。因此，右心室容量与左心室容量的解释需要仔细定义准确的呼吸时间点，以便在休息时和运动期间进行正确的解释。
Breathing-induced changes in intrathoracic pressures influence left ventricular (LV) and right ventricular (RV) volumes, the exact nature and extent of which have not previously been evaluated in humans. We sought to examine this "respiratory pump" using novel real-time cardiac magnetic resonance (CMR) imaging. Eight healthy subjects underwent serial multislice real-time CMR during normal breathing, breath holding, and the Valsalva maneuver. Subsequently, a separate cohort of nine subjects underwent real-time CMR at rest and during incremental exercise. LV and RV end-diastolic volume (EDV) and end-systolic volume (ESV) and diastolic and systolic eccentricity indexes were determined at peak inspiration and expiration. During normal breathing, inspiration resulted in an increase in RV volumes [RVEDV: +18 +/- 8%, RVESV: +14 +/- 12%, and RV stroke volume (SV): +21 +/- 10%, P < 0.01] and an opposing decrease in LV volumes (P < 0.0001 for interaction). During end-inspiratory breath holding, RV SV decreased by 9 +/- 10% (P = 0.046), whereas LV SV did not change. During the Valsalva maneuver, volumes decreased in both ventricles (RVEDV: -29 +/- 11%, RVESV: -16 +/- 14%, RV SV: -36 +/- 14%, LVEDV: -22 +/- 17%, and LV SV: -25 +/- 17%, P < 0.01). The reciprocal effect of respiration on LV and RV volumes was maintained throughout exercise. The diastolic and systolic eccentricity indexes were greater during inspiration than during expiration, both at rest and during exercise (P < 0.0001 for both). In conclusion, ventricular volumes oscillate with respiratory phase such that RV and LV volumes are maximal at peak inspiration and expiration, respectively. Thus, interpretation of RV versus LV volumes requires careful definition of the exact respiratory time point for proper interpretation, both at rest and during exercise.