### Abstract

Left ventricular (LV) O_{2} consumption (VO_{2}) per minute is measurable for both regular and arrhythmic beats. LV VO_{2} per beat can then be obtained as VO_{2} per minute divided by heart rate per minute for regular beats, but not for arrhythmic beats. We have established that VO_{2} of a regular stable beat is predictable by VO_{2} = a PVA + b E_{max} + c, where PVA is the systolic pressure-volume area as a measure of the total mechanical energy of an individual contraction and E _{max} is the end-systolic maximum elastance as an index of ventricular contractility of the contraction. Furthermore, a is the O_{2} cost of PVA, b is the O_{2} cost of E_{max}, and c is the basal metabolic VO_{2} per beat. We considered it theoretically reasonable to expect that the same formula could also predict LV VO_{2} of individual arrhythmic beats from their respective PVA and E_{max} with the same a, b, and c. We therefore applied this formula to the PVA - E_{max} data of individual arrhythmic beats under electrically induced atrial fibrillation (AF) in six canine in situ hearts. We found that the predicted VO_{2} of individual arrhythmic beats highly correlated linearly with either their VO _{2} (r = 0.96 ± 0.01) or E_{max} (0.97 ± 0.03) while both also highly correlated linearly with each other (0.88 ± 0.04). This suggests that the above formula may be used to predict LV VO_{2} of absolute arrhythmic beats from their E_{max} and PVA under AF.

Original language | English |
---|---|

Pages (from-to) | 135-142 |

Number of pages | 8 |

Journal | Japanese Journal of Physiology |

Volume | 55 |

Issue number | 2 |

DOIs | |

Publication status | Published - Apr 2005 |

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### Keywords

- Arrhythmia
- Cardiac function
- Mechanoenergetics
- Oxygen consumption

### ASJC Scopus subject areas

- Physiology

### Cite this

*Japanese Journal of Physiology*,

*55*(2), 135-142. https://doi.org/10.2170/jjphysiol.R2099

**Predictability of O2 consumption from contractility and mechanical energy of absolute arrhythmic beats in canine heart.** / Shimizu, Juichiro; Mohri, Satoshi; Iribe, Gentaro; Ito, Haruo; Morita, Terumasa; Yamaguchi, Hiroki; Sano, Shunji; Suga, Hiroyuki.

Research output: Contribution to journal › Article

*Japanese Journal of Physiology*, vol. 55, no. 2, pp. 135-142. https://doi.org/10.2170/jjphysiol.R2099

}

TY - JOUR

T1 - Predictability of O2 consumption from contractility and mechanical energy of absolute arrhythmic beats in canine heart

AU - Shimizu, Juichiro

AU - Mohri, Satoshi

AU - Iribe, Gentaro

AU - Ito, Haruo

AU - Morita, Terumasa

AU - Yamaguchi, Hiroki

AU - Sano, Shunji

AU - Suga, Hiroyuki

PY - 2005/4

Y1 - 2005/4

N2 - Left ventricular (LV) O2 consumption (VO2) per minute is measurable for both regular and arrhythmic beats. LV VO2 per beat can then be obtained as VO2 per minute divided by heart rate per minute for regular beats, but not for arrhythmic beats. We have established that VO2 of a regular stable beat is predictable by VO2 = a PVA + b Emax + c, where PVA is the systolic pressure-volume area as a measure of the total mechanical energy of an individual contraction and E max is the end-systolic maximum elastance as an index of ventricular contractility of the contraction. Furthermore, a is the O2 cost of PVA, b is the O2 cost of Emax, and c is the basal metabolic VO2 per beat. We considered it theoretically reasonable to expect that the same formula could also predict LV VO2 of individual arrhythmic beats from their respective PVA and Emax with the same a, b, and c. We therefore applied this formula to the PVA - Emax data of individual arrhythmic beats under electrically induced atrial fibrillation (AF) in six canine in situ hearts. We found that the predicted VO2 of individual arrhythmic beats highly correlated linearly with either their VO 2 (r = 0.96 ± 0.01) or Emax (0.97 ± 0.03) while both also highly correlated linearly with each other (0.88 ± 0.04). This suggests that the above formula may be used to predict LV VO2 of absolute arrhythmic beats from their Emax and PVA under AF.

AB - Left ventricular (LV) O2 consumption (VO2) per minute is measurable for both regular and arrhythmic beats. LV VO2 per beat can then be obtained as VO2 per minute divided by heart rate per minute for regular beats, but not for arrhythmic beats. We have established that VO2 of a regular stable beat is predictable by VO2 = a PVA + b Emax + c, where PVA is the systolic pressure-volume area as a measure of the total mechanical energy of an individual contraction and E max is the end-systolic maximum elastance as an index of ventricular contractility of the contraction. Furthermore, a is the O2 cost of PVA, b is the O2 cost of Emax, and c is the basal metabolic VO2 per beat. We considered it theoretically reasonable to expect that the same formula could also predict LV VO2 of individual arrhythmic beats from their respective PVA and Emax with the same a, b, and c. We therefore applied this formula to the PVA - Emax data of individual arrhythmic beats under electrically induced atrial fibrillation (AF) in six canine in situ hearts. We found that the predicted VO2 of individual arrhythmic beats highly correlated linearly with either their VO 2 (r = 0.96 ± 0.01) or Emax (0.97 ± 0.03) while both also highly correlated linearly with each other (0.88 ± 0.04). This suggests that the above formula may be used to predict LV VO2 of absolute arrhythmic beats from their Emax and PVA under AF.

KW - Arrhythmia

KW - Cardiac function

KW - Mechanoenergetics

KW - Oxygen consumption

UR - http://www.scopus.com/inward/record.url?scp=24944443841&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24944443841&partnerID=8YFLogxK

U2 - 10.2170/jjphysiol.R2099

DO - 10.2170/jjphysiol.R2099

M3 - Article

C2 - 15899066

AN - SCOPUS:24944443841

VL - 55

SP - 135

EP - 142

JO - Journal of Physiological Sciences

JF - Journal of Physiological Sciences

SN - 1880-6546

IS - 2

ER -