Heart rate reduction with esmolol is associated with improved arterial elastance in patients with septic shock: a prospective observational study.
OBJECTIVE
Ventricular-arterial (V-A) decoupling decreases myocardial efficiency and is exacerbated by tachycardia that increases static arterial elastance (Ea). We thus investigated the effects of heart rate (HR) reduction on Ea in septic shock patients using the beta-blocker esmolol. We hypothesized that esmolol improves Ea by positively affecting the tone of arterial vessels and their responsiveness to HR-related changes in stroke volume (SV).


METHODS
After at least 24 h of hemodynamic optimization, 45 septic shock patients, with an HR ≥95 bpm and requiring norepinephrine to maintain mean arterial pressure (MAP) ≥65 mmHg, received a titrated esmolol infusion to maintain HR between 80 and 94 bpm. Ea was calculated as MAP/SV. All measurements, including data from right heart catheterization, echocardiography, arterial waveform analysis, and norepinephrine requirements, were obtained at baseline and at 4 h after commencing esmolol.


RESULTS
Esmolol reduced HR in all patients and this was associated with a decrease in Ea (2.19 ± 0.77 vs. 1.72 ± 0.52 mmHg l(-1)), arterial dP/dt max (1.08 ± 0.32 vs. 0.89 ± 0.29 mmHg ms(-1)), and a parallel increase in SV (48 ± 14 vs. 59 ± 18 ml), all p < 0.05. Cardiac output and ejection fraction remained unchanged, whereas norepinephrine requirements were reduced (0.7 ± 0.7 to 0.58 ± 0.5 µg kg(-1) min(-1), p < 0.05).


CONCLUSIONS
HR reduction with esmolol effectively improved Ea while allowing adequate systemic perfusion in patients with severe septic shock who remained tachycardic despite standard volume resuscitation. As Ea is a major determinant of V-A coupling, its reduction may contribute to improving cardiovascular efficiency in septic shock.
Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, "La Sapienza", Policlinico Umberto Primo, Viale del Policlinico 155, 00161, Rome, Italy. andrea.morelli@uniroma1.it.
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Morelli
Bloomsbury Institute of Intensive Care Medicine, University College London, Cruciform Building, London, WC1E 6BT, UK.
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Singer
Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, "La Sapienza", Policlinico Umberto Primo, Viale del Policlinico 155, 00161, Rome, Italy.
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Ranieri
Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, "La Sapienza", Policlinico Umberto Primo, Viale del Policlinico 155, 00161, Rome, Italy.
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D'Egidio
Department of Medico-Surgical Sciences and Biotechnologies, University of Rome "La Sapienza", Corso della Repubblica, 79, 04100, Latina, Italy.
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Mascia
Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, "La Sapienza", Policlinico Umberto Primo, Viale del Policlinico 155, 00161, Rome, Italy.
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Orecchioni
Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, "La Sapienza", Policlinico Umberto Primo, Viale del Policlinico 155, 00161, Rome, Italy.
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Piscioneri
Department of Anesthesia and Intensive Care, Cardiothoracic Anesthesia and Intensive Care Medicine, University Hospital of Pisa, via Roma 55, 56126, Pisa, Italy.
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Guarracino
Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, "La Sapienza", Policlinico Umberto Primo, Viale del Policlinico 155, 00161, Rome, Italy.
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Greco
Department of Medico-Surgical Sciences and Biotechnologies, University of Rome "La Sapienza", Corso della Repubblica, 79, 04100, Latina, Italy.
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Peruzzi
Department of Medico-Surgical Sciences and Biotechnologies, University of Rome "La Sapienza", Corso della Repubblica, 79, 04100, Latina, Italy.|Department of AngioCardioNeurology, IRCCS Neuromed, Via Atinense 18, 86077, Pozzilli, Italy.
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Biondi-Zoccai
Department of Medico-Surgical Sciences and Biotechnologies, University of Rome "La Sapienza", Corso della Repubblica, 79, 04100, Latina, Italy.|Department of AngioCardioNeurology, IRCCS Neuromed, Via Atinense 18, 86077, Pozzilli, Italy.
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Frati
Unit of Internal Medicine and Cardiology, Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla, 3, 50134, Florence, Italy.
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Romano
D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D004452:Echocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000627:therapeutic use; D011412:Propanolamines / Q000008:administration & dosage*; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000503:physiopathology*; D012772:Shock, Septic / Q000503:physiopathology*; D013318:Stroke Volume / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000627:therapeutic use
D058671:Adrenergic beta-1 Receptor Antagonists; D011412:Propanolamines; D014662:Vasoconstrictor Agents; C036604:esmolol; D009638:Norepinephrine
Arterial elastance; Beta-adrenergic receptors; Dicrotic notch; Heart rate; Septic shock; Tachycardia; Ventricular-arterial coupling