Differential diagnosis is challenging in poor conditioned neonates referred to the emergency room. Infectious disease is common, yet tachycardia should alert the clinician to look for cardiac arrhythmia and comprise. Tachycardia can lead to cardiomyopathy and should warrant further diagnostics for myocarditis, especially in rare or unusual combination of arrhythmias.

BackgroundThere is a long-standing debate about the role of beta-adrenoceptor polymorphisms in the cardiovascular system. We wanted to elucidate whether β1-adrenoceptor-polymorphisms affects the postoperative catecholamine consumption and the length of intermediate care unit stay in patients undergoing cardiac surgery, and whether this might be enhanced or attenuated by catechol-O-methyl-transferase (COMT) polymorphism.Material/MethodsWe included 116 patients (63±1.2 years; 34% females; 81±1 kg) undergoing cardiac surgery. We assessed Arg389Gly and Ser49Gly-β1-adrenoceptor (B1AR) polymorphism together with Val158Met-COMT polymorphism by real-time PCR using fluorescence resonance energy transfer (PCR-FRET). The preoperative risk was assessed by EuroSCORE. In addition, we measured the endogenous preoperative epinephrine and norepinephrine plasma concentrations using an electrochemical HPLC method.Results84.6% were homozygous for Ser49Ser, 52.1% homozygous for Arg389Arg B1AR, and 32.5% for Val158Val-COMT, while 15.4% showed Ser49Gly B1AR, 38.5% Arg389Gly-B1AR, and 35.6% Val158Met-COMT. We found that the Gly49-variant, the Gly389-variant, and the Val158-COMT-variant were associated with higher postoperative norepinephrine consumption. All patients carrying the Val158-COMT allele exhibited higher preoperative norepinephrine concentrations. Moreover, we found that both β1-adrenoceptor polymorphisms were associated with a longer stay in hospital, which was modulated by the COMT polymorphism.ConclusionsThese data show that the β1-adrenoceptor polymorphisms, together with the COMT polymorphism, affect norepinephrine consumption and stay in hospital in a situation of enhanced cardiovascular stress, reflected here by the postoperative period after cardiac surgery. Moreover, we conclude that patients with the Val158-COMT genotype exhibit higher endogenous resting plasma norepinephrine levels.

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