Low-dose steroid-induced bradyarrhythmias and treatment refractory hypokalaemia: a case report

2020 ◽  
pp. 1-3 ◽  
Author(s):  
Arindam Ghosh ◽  
Saba Annigeri ◽  
Anupama Nair
Keyword(s):  
Adverse Effect ◽  
Heart Rate ◽  
Cardiac Arrhythmias ◽  
Low Dose ◽  
High Dose ◽  
Methyl Prednisolone ◽  
Pulse Dose ◽  
Rapid Control ◽  
Treatment Refractory ◽  
Mineralocorticoid Activity

Abstract Corticosteroid therapy has become an important modality of treatment for diseases in which rapid control of immunoinflammatory processes is required. However, one of the serious, but less known adverse effect of this therapy is cardiac arrhythmias. This includes both tachyarrhythmias and bradyarrhythmias. Corticosteroid use may also be associated with electrolyte imbalances like hypokalaemia by its mineralocorticoid activity. Those side effects are mainly seen with high-dose intravenous methyl-prednisolone or oral pulse dose prednisolone therapy. Here we report our experience in a child with warm idiopathic autoimmune haemolytic anaemia who developed sinus bradyarrhythmias and treatment refractory hypokalaemia during low-dose steroid therapy with reduction in heart rate by 60% of baseline.

Sedative and physiologic effects of tiletamine–zolazepam following buccal administration in cats

2019 ◽  
Vol 22 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Pablo Nejamkin ◽  
Verónica Cavilla ◽  
María Clausse ◽  
Florencia Landivar ◽  
Augusto M Lorenzutti ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Low Dose ◽  
Sedation Score ◽  
High Dose ◽  
Physiological Effects ◽  
Chemical Restraint ◽  
Hemoglobin Saturation ◽  
Baseline Systolic Blood Pressure ◽  
Over Time

Objectives The aim of this study was to describe the sedative and some physiological effects of tiletamine–zolazepam following buccal administration (BA) in cats. Methods Seven healthy spayed European shorthair cats (three males, four females) were studied twice in this randomized, blinded, crossover study. Each cat received two doses of tiletamine–zolazepam by BA: the low-dose (LD) group consisted of 5 mg/kg of each drug, and the high-dose (HD) group consisted of 7.5 mg/kg of each. Baseline systolic blood pressure (SAP), heart rate (HR), respiratory rate (RR) and a sedation score were recorded prior to administration of each treatment. The same variables plus the percentage of hemoglobin saturated with oxygen as measured by pulse oximetry (SpO2) were recorded at predefined intervals for the next 2 h. Results All cats completed the study. No retching or vomiting were observed. Hypersalivation was observed in 0/7 and 3/7 for LD and HD groups, respectively ( P = 0.2). There were significant changes in scores over time for posture, response to clippers and response to manual restraint for both groups, without differences between groups. RR, HR and SAP changed significantly over time. SAP and RR were significantly lower for the HD than for the LD group. No values for hemoglobin saturation <95% were observed. Conclusions and relevance BA of tiletamine–zolazepam at the doses studied here is a simple and effective method for chemical restraint in cats, where the LD group had a lower impact on SAP and RR than the HD group.

scholarly journals The dose-dependent effect of chronic Verapamil treatment on cardiac function in isolated rat heart with Hypertension

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
S Simovic ◽  
J Jeremic ◽  
G Davidovic ◽  
I Srejovic ◽  
V Zivkovic ◽  
...  
Keyword(s):  
Heart Rate ◽  
Rat Heart ◽  
Coronary Flow ◽  
Chronic Treatment ◽  
Low Dose ◽  
Isolated Rat Heart ◽  
High Dose ◽  
Chronotropic Effects ◽  
Dose Dependent ◽  
Isolated Rat

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Verapamil, a calcium channel blocker, is used for treatment of hypertension, paroxysmal supraventricular tachycardia  and angina pectoris. It primarily blocks L-type calcium channels preventing excessive influx of calcium into cardiomyocytes, leading to negative inotropic effect, and smooth muscle cells resulting in reduced relaxation of vasculature. With calcium antagonism it also causes negative chronotropic effect. However, there is no data on it’s dose-dependent effects on cardiac dynamic parameters and heart rate on isolated rat heart with hypertension. Purpose To investigate chronic, dose-dependent effects of Verapamil on cardiodynamic parameters in isolated rat heart with hypertension. Methods The present 4-week study was carried out on 24 spontaneously hypertensive Wistar Kyoto male rats  (6 weeks old): Control (n = 6), rats treated with 0.5 mg/kg/day of Verapamil (n = 6), rats treated with 5 mg/kg/day of Verapamil (n = 6) and rats treated with 50 mg/kg/day of Verapamil (n = 6). Isolated rat hearts were perfused on Langendorff perfusion apparatus. Results Chronic, low-dose Verapamil treatment significantly depressed function of all cardiodynamic parameters of the hypertensive heart when compared to the rats treated with higher doses of Verapamil (p &lt; 0.001), except on the coronary flow and heart rate when compared to the Control (p= 0.137; p = 1.000, respectively). There was no significant differences between Verapamil in middle dose (5 mg/kg/day) and the Control group in inotropic (p = 0.415) and lusitropic (p = 1.000) effects, while it significantly lowered values of coronary flow (p = 0.002). It achieved significantly lower inotropic, lusitropic and chronotropic effects (p &lt; 0.001) than high Verapamil dose and significantly better inotropic (p = 0.017), lusitropic (p &lt; 0.001), but not chronotropic effects than low-dose Verapamil treatment (p = 0.179). High-dose, chronic treatment with Verapamil significantly intensified function of  the isolated rat heart with hypertension when compared to Control and lower doses of Verapamil (p &lt; 0.001), without significant effects on coronary flow (p = 0.363). Conclusions Chronic treatment with Verapamil in high dose achieved better inotropic, chronotropic and lusitropic effects than treatment in low and middle doses of Verapamil, without significant effects on coronary flow. There is dose-depended effect of chronic Verapamil treatment on cardiac function of isolated rat heart with hypertension.

Effects of Perioperative Dexmedetomidine Infusion in Patients Undergoing Vascular Surgery 

1995 ◽  
Vol 82 (3) ◽  
pp. 620-633 ◽  
Author(s):  
P. Talke ◽  
J. Li ◽  
U. Jain ◽  
J. Leung ◽  
K. Drasner ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Vascular Surgery ◽  
Low Dose ◽  
Plasma Concentrations ◽  
Surgical Patients ◽  
High Dose ◽  
Hemodynamic Management ◽  
Myocardial Wall Motion ◽  
Medium Dose

Background Dexmedetomidine, a highly selective alpha 2-adrenergic agonist, increases perioperative hemodynamic stability in healthy patients but decreases blood pressure and heart rate. The goal of this study was to evaluate, in a preliminary manner, the hemodynamic effects of perioperatively administered dexmedetomidine in surgical patients at high risk for coronary artery disease. Methods Twenty-four vascular surgery patients received a continuous infusion of placebo or one of three doses of dexmedetomidine, targeting plasma concentrations of 0.15 ng/ml (low dose), 0.30 ng/ml (medium dose), or 0.45 ng/ml (high dose) from 1 h before induction of anesthesia until 48 h postoperatively. All patients received standardized anesthesia and hemodynamic management. Blood pressure, heart rate, and Holter ECG were monitored; additional monitoring included continuous 12-lead ECG preoperatively, anesthetic concentrations and myocardial wall motion (echocardiography) intraoperatively, and cardiac enzymes postoperatively. Results Preoperatively, there was a decrease in heart rate (low dose 11%, medium dose 5%, high dose 20%) and systolic blood pressure (low dose 3%, medium dose 12%, high dose 20%) in patients receiving dexmedetomidine. Intraoperatively, dexmedetomidine groups required more vasoactive medications to maintain hemodynamics within predetermined limits. Postoperatively, demedetomidine groups had less tachycardia (minutes/monitored hours) than the placebo group (placebo 23 min/h; low dose 9 min/h, P = 0.006; medium dose 0.5 min/h, P = 0.004; high dose 2.3 min/h, P = 0.004). Bradycardia was rare in all groups. There were no myocardial infarctions or discernible trends in the laboratory results. Conclusions Infusion of dexmedetomidine up to a targeted plasma concentration of 0.45 ng/ml appears to benefit perioperative hemodynamic management of surgical patients undergoing vascular surgery but required greater intraoperative pharmacologic intervention to support blood pressure and heart rate.

Changes in the arterial blood pressure, heart rate and normal ECG parameters of rat after envenomation with Egyptian cobra (Naja haje) venom

1997 ◽  
Vol 16 (6) ◽  
pp. 327-333 ◽  
Author(s):  
Mohamed Alaa A Omran ◽  
Ismail M Abdel-Nabi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Electrical Activity ◽  
Arterial Blood Pressure ◽  
Wave Amplitude ◽  
Low Dose ◽  
High Dose ◽  
T Wave ◽  
Arterial Blood ◽  
Naja Haje

1 The effect of Egyptian cobra (Naja haje) venom on the normal electrical activity of the cardiac muscles (ECG) and arterial blood pressure of envenomated rats were investigated in this study. 2 Rats were divided into three groups. The first group was injected im with saline and considered as control group. Rats of the second and third groups were injected IM with 0.02 μg and 0.04 μg cobra venom/ gim b.wt, respectively. 3 Mean blood pressure (MBP), heart rate (HR) and four different ECG parameters (PR and QT intervals, R and T wave amplitudes) were measured over 1 h following envenomation. 4 The low dose (0.02 μg/g) of N. haje venom caused hypotension accompanied by an increase in the HR, whereas hypertension and bradycardia developed after injection of the high dose (0.04 μg/g) of venom. 5 There was a decrease in the P-R interval after administration of the low dose and prolongation of it after the high dose. The Q-T interval and R-wave amplitude were significantly increased after injection of both doses. T-wave amplitude was significantly elevated only after injection of the high dose. 6 The present results indicate that the Egyptian cobra (N. haje) venom significantly alters the arterial blood pressure and ECG parameters of envenomated rats. This suggests that impairment of the electrical activity of cardiac muscle may be one of the reasons why victims of cobra bite die.

scholarly journals Candidalysin impedes the development of embryonic zebrafish (Danio rerio)

2021 ◽  
Author(s):  
Jing Shen ◽  
JingCong Tan ◽  
Haochun Shi ◽  
Jie Zhou ◽  
Yanbin Zhao ◽  
...  
Keyword(s):  
Heart Rate ◽  
Fungal Pathogen ◽  
Chronic Exposure ◽  
Low Dose ◽  
Aquatic Organisms ◽  
High Dose ◽  
Hatching Rate ◽  
Human Fungal Pathogen ◽  
Developmental Effects ◽  
First Time

Abstract Candidalysin is a cytolytic peptide secreted by Candida albicans, an opportunistic human fungal pathogen that was widely spread in clinic and in the environment. However, its impacts on the development of aquatic organisms remain limited. Herein, we explored the developmental effects of candidalysin on embryonic zebrafish at concentrations from 0.008 to 160 mg/L. In acute exposure, decreased survival rate with EC50 at 49.5 mg/L were observed. Meanwhile, in high-dose exposure groups (5-160 mg/L), an increased swimming frequency were observed at candidalysin concentrations of 10 mg/L and above. In chronic exposure, decreased spontaneous contraction, hatching rate and heart rate were identified in low-dose exposure groups (0.008-5 mg/L). Especially for the heart rate, significant changes were observed at candidalysin concentrations as low as 0.008 mg/L (environmentally relevant). The present study first time pointed out the developmental toxicities of candidalysin on fish that was rarely investigated, and thus contributed to its environmental risk assessment.

scholarly journals Efficacy of a Low Dose of Estrogen on Antioxidant Defenses and Heart Rate Variability

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Cristina Campos ◽  
Karina Rabello Casali ◽  
Dhãniel Baraldi ◽  
Adriana Conzatti ◽  
Alex Sander da Rosa Araújo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Superoxide Anion ◽  
Low Dose ◽  
Estrogen Therapy ◽  
Antioxidant Defenses ◽  
High Dose ◽  
Hemodynamic Assessment

This study tested whether a low dose (40% less than the pharmacological dose of 17-βestradiol) would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n=9/group) were divided in three groups: (1) ovariectomized (Ovx), (2) ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg), and (3) high dose (HE; 0.5 mg) 17-βestradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD) and catalase (CAT) activities, redox ratio (GSH/GSSG), total radical-trapping antioxidant potential (TRAP), hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.

scholarly journals Effects of chronic exposure to usual and high doses of Bisphenol A on cardiac arrhythmias, electrophysiology, and autonomic modulation

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
A Scridon ◽  
A I Balan ◽  
V B Halatiu ◽  
B A Finascu ◽  
D A Cozac ◽  
...  
Keyword(s):  
Heart Rate ◽  
Bisphenol A ◽  
Action Potential ◽  
Cardiac Arrhythmias ◽  
Chronic Exposure ◽  
Ventricular Arrhythmias ◽  
Human Exposure ◽  
High Dose ◽  
Autonomic Modulation ◽  
Premature Beats

Abstract Background Bisphenol A (BPA) is a synthetic compound found in plastic bottles, sports equipment, or water pipes. The continuous and inevitable human exposure to BPA has been related to increased cardiovascular risk. In experimental studies, acute exposure to high BPA doses was associated with ventricular arrhythmias. However, the effects of chronic exposure to usual BPA doses (i.e., relevant for usual human exposure) on cardiac arrhythmogenicity have not been properly assessed. Purpose We aimed to assess the effects of chronic exposure to high and usual BPA doses on cardiac arrhythmias, electrophysiology, and autonomic modulation in rats. Methods Adult female Wistar rats were randomized into 3 groups: Control, BPA, and BPA-HD (n=7 each). BPA and BPA-HD rats received 50 μg/kg/day and 25 mg/kg/day of BPA, respectively, for 9 weeks. Rats were implanted with radiotelemetry ECG devices and 24-h ECG recordings were performed prior to and after application of transesophageal atrial burst pacing (4,000 stimuli/min for 20 s; 15 cycles). Heart rate variability (HRV) parameters and atrial and ventricular arrhythmias (i.e., atrial premature beats [APB], atrial fibrillation [AF], ventricular premature beats [VPB], ventricular tachycardia/fibrillation [VT/VF]) were assessed based on the 24-h ECG recordings. The left atrium was then collected and atrial depolarization velocity and action potential duration to 90% (APD90) and 50% (APD50) of complete repolarization were measured. Results Mean heart rate (p=0.48), the number of VPB (p=0.90), AF inducibility (p=0.68), and atrial action potential parameters (all p&gt;0.05) were all similar between the 3 groups. None of the animals presented VT/VF. There was no significant difference in the number of atrial or ventricular arrhythmic events nor in the HRV parameters between BPA and Control (all p&gt;0.05). However, BPA-HD presented a significantly higher number of APB both prior to (p=0.02) and after (p=0.04) atrial pacing, and a significantly higher number of post-pacing spontaneous AF episodes (p&lt;0.01) compared to Control. The parasympathetic indexes SDNN, RMSSD, pNN5, and the NHF of the HRV spectrum were all significantly higher (all p&lt;0.05), whereas the LF/HF ratio, an index of sympathetic and parasympathetic interactions, was significantly lower (p=0.01) in the BPA-HD compared with the Control rats. Conclusions In rats, chronic exposure to BPA doses relevant for usual human exposure was not associated in any significant change in cardiac arrhythmogenicity, electrophysiology, or autonomic modulation. However, high-dose BPA exposure, such as that occurring in workers in the plastics industry, led to significant increase in atrial arrhythmogenicity, including AF, that did not seem to be related to atrial electrophysiology changes. Instead, given the strong atrial proarrhythmic effects of vagal hyperactivity, this effect could be linked to the significant increase in vagal modulation induced by high-dose BPA exposure. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS – UEFISCDI

Hemodynamic response to vasopressin during V1-receptor antagonism in baroreflex-deficient subjects

1995 ◽  
Vol 268 (1) ◽  
pp. R156-R163 ◽  
Author(s):  
K. M. Huch ◽  
K. R. Runyan ◽  
B. M. Wall ◽  
H. Gavras ◽  
C. R. Cooke
Keyword(s):  
Heart Rate ◽  
Nervous System ◽  
Low Dose ◽  
Plasma Renin ◽  
High Dose ◽  
Receptor Blockade ◽  
Control Subjects ◽  
Vasodilatory Effect ◽  
Sympathetic Nervous ◽  
And Control

Six quadriplegic subjects and 6 control subjects received high-dose arginine vasopressin (AVP) infusions at rates of 500, 1,000, 2,000, and 4,000 microU.kg-1.min-1 in consecutive 10-min intervals. Six additional quadriplegic subjects received low-dose AVP infusions at rates of 50, 100, 200, 400, and 800 microU.kg-1.min-1. All subjects were studied once with and once without administration of a selective V1-receptor antagonist. During high-dose AVP infusions without V1-receptor blockade, mean arterial pressure (MAP) increased from 80 +/- 4 to 87 +/- 5 mmHg (P < 0.05) in quadriplegic subjects but was unchanged in control subjects. In the presence of V1-receptor blockade, MAP decreased from 75 +/- 4 to 58 +/- 4 mmHg (P < 0.001), and heart rate (HR) increased from 61 +/- 5 to 80 +/- 5 beats/min (P < 0.001) in quadriplegic subjects. In the studies on control subjects, MAP decreased only from 75 +/- 3 to 72 +/- 5 mmHg (P < 0.05), whereas HR increased from 64 +/- 4 to 87 +/- 4 beats/min (P < 0.001). Plasma renin activity (PRA) increased in both quadriplegic and control subjects. The effects of low-dose AVP infusions on MAP, HR, and PRA in quadriplegic subjects were similar to those observed during high-dose infusions. Thus, in the absence of baroreceptor-mediated sympathetic nervous system responses, a vasodilatory effect of AVP that is capable of producing marked reductions in MAP can be demonstrated in the presence of V1-receptor blockade.

A brachytherapia szerepe az ajak-szájüregi daganatok kuratív ellátásában

2021 ◽  
Vol 162 (37) ◽  
pp. 1471-1479
Author(s):  
Örs Ferenczi ◽  
Tibor Major ◽  
Zoltán Takácsi-Nagy
Keyword(s):  
Oral Cavity ◽  
Dose Rate ◽  
Low Dose ◽  
High Dose Rate ◽  
Therapeutic Modality ◽  
Tumor Control ◽  
External Irradiation ◽  
High Dose ◽  
Low Dose Rate ◽  
Pulse Dose

Összefoglaló. A szájüregi daganatok kuratív kezelésében az elsődlegesen választandó műtét mellett a sugárterápiának is jelentős szerepe van. A lokális tumormentesség biztosításához azonban dóziseszkaláció szükséges. Ennek külső besugárzással való megvalósítása a környező normálszövetek fölösleges dózisterhelésével és az ebből következő mellékhatások előfordulásának emelkedésével jár. A brachytherapia (BT) – amelynek során radioaktív sugárforrást/sugárforrásokat juttatunk a tumorba vagy annak közelébe – lehetővé teszi a helyileg magasabb dózis leadását a környező ép szövetek kímélésével. A BT a korai, T1–2N0 stádiumú szájüregi tumoroknál – kedvező prognosztikai faktorok mellett – akár kizárólagosan vagy mint posztoperatíve egyedül alkalmazott terápiás modalitás jön szóba. Kedvezőtlenebb prognózis esetén vagy előrehaladottabb stádiumban (T3–4 vagy N+) a műtétet és/vagy a percutan irradiációt kiegészítő eljárásként alkalmazható kedvező sugárfizikai tulajdonságai miatt. A kis dózisteljesítményű (low-dose-rate, LDR) BT-t már évtizedek óta alkalmazzák a terápiában, de ezt kezdi kiszorítani a nagy dózisteljesítményű (high-dose-rate, HDR), illetve a pulzáló dózisteljesítményű (pulse-dose-rate, PDR) BT. A jelen áttekintő tanulmány célja irodalmi adatok alapján a BT szerepének és indikációjának ismertetése a szájüregi daganatok kuratív kezelésében, alrégiókra lebontva. Orv Hetil. 2021; 162(37): 1471–1479. Summary. Radiation therapy plays a significant role in the curative treatment of oral cavity tumors, in addition to the primary choice of surgery. However, dose escalation is required to ensure local tumor control. Its implementation with external irradiation is accompanied by an unnecessary dose exposure to the surrounding normal tissues and an increase in the incidence of consequent side effects. Brachytherapy (BT), in which a radiation source/sources is/are placed inside or close to the tumor, allows a higher dose to be delivered locally, sparing the surrounding intact tissues. In addition to favorable prognostic factors in early T1–2N0 stage oral cavity tumors, BT is considered either exclusively or as a sole postoperative therapeutic modality. At less favorable prognosis or at a more advanced stage (T3–4 or N+), BT can be used as a complementary procedure after surgery and/or percutaneous irradiation based on its favorable radio-physical properties. Low-dose-rate (LDR) BT has been used in the therapy for decades, but recently it has been replaced by high-dose-rate (HDR) and pulse-dose-rate (PDR) BT. The purpose of this review is to describe the role and indications of BT in the treatment of oral cavity tumors categorized into subregions, based on the literature data. Orv Hetil. 2021; 162(37): 1471–1479.

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