Heart Block Second Degree Publications (1420)


Heart Block Second Degree Publications

J Toxicol Sci
J Toxicol Sci 2017 ;42(1):31-42
Drug Safety, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd.

This study sought to clarify the effects of reduced feeding on physiological parameters in dogs to enable appropriate evaluations of the safety and toxicity of test compounds. We measured alkaline phosphatase isozymes and the circulating blood volume, as well as clinical signs, body weight, hematology, blood chemistry, electrocardiography, organ weight, and histopathology, in male beagle dogs fed a diet consisting of 300 g/day or 150 g/day for 4 weeks. There were no abnormal clinical signs in any of the dogs. Read More

In the 150-g/day feeding group, a decreased alkaline phosphatase 3 suggesting effects on the bone and a decreased circulating blood volume associated with body weight loss were observed. Additionally, the following changes were also observed in the 150-g/day group: a decrease in body weight; hematologic changes including decreases in white blood cells, neutrophils, red blood cells, hemoglobin, hematocrit and reticulocytes; blood chemical changes including decreases in aspartate aminotransferase, lactate dehydrogenase and calcium and an increase in the creatinine at week 1 or thereafter; electrocardiographic changes including a decrease in the heart rate, a prolonged QRS duration and the occurrence of a second-degree atrioventricular block at week 3 or thereafter; and pathological changes including decreases in the weights of the liver and thymus, a decrease in hepatocyte rarefaction, and thymic atrophy. These results provide useful information for assessing the safety of compounds in toxicological studies, enabling direct treatment effects and secondary changes caused by decreased food intake to be distinguished.

The study objective was to determine the predictors of new-onset arrhythmia among infants with single-ventricle anomalies during the post-Norwood hospitalization and the association of those arrhythmias with postoperative outcomes (ventilator time and length of stay) and interstage mortality.
After excluding patients with preoperative arrhythmias, we used data from the Pediatric Heart Network Single Ventricle Reconstruction Trial to identify risk factors for tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia) and atrioventricular block (second or third degree) among 544 eligible patients. We then determined the association of arrhythmia with outcomes during the post-Norwood hospitalization and interstage period, adjusting for identified risk factors and previously published factors. Read More

Tachyarrhythmias were noted in 20% of subjects, and atrioventricular block was noted in 4% of subjects. Potentially significant risk factors for tachyarrhythmia included the presence of modified Blalock-Taussig shunt (P = .08) and age at Norwood (P = .07, with risk decreasing each day at age 8-20 days); the only significant risk factor for atrioventricular block was undergoing a concomitant procedure at the time of the Norwood (P = .001), with the greatest risk being in those undergoing a tricuspid valve procedure. Both tachyarrhythmias and atrioventricular block were associated with longer ventilation time and length of stay (P < .001 for all analyses). Tachyarrhythmias were not associated with interstage mortality; atrioventricular block was associated with mortality among those without a pacemaker in the unadjusted analysis (hazard ratio, 2.3; P = .02), but not after adding covariates.
Tachyarrhythmias are common after the Norwood procedure, but atrioventricular block may portend a greater risk for interstage mortality.

Acta Neurol. Scand.
Acta Neurol Scand 2017 Jan 8;135(1):129-133. Epub 2016 Mar 8.
Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.

Assessment of sinoatrial node function after Maze III procedure combined with a mitral valve operation.
100 patients were included in the research with persistent and long-standing persistent forms of atrial fibrillation (AF) and need of operative treatment concerning valve disease. The following preoperative preparation methods were executed to all patients: Electrocardiogram in 12 standard assignments;Two-dimensional echocardiographic with assessment of systolic and diastolic functions of the left ventricle, size of the left atrium and grade of valve disease;Transesophageal echocardiography for exclusion of blood clots in the left atrium and left atrial appendage;Coronary angiography for exclusion of coronary heart disease;Computer tomography for examination of cardiac chambers and anatomic characteristics of pulmonary veins. Read More

Electric cardioversion in X-ray operating room conditions was performed on all patients. After successful restoration of sinus rhythm, electrophysiological examination (EP) of heart was carried out. Then, on the first or second day after EP study, Maze III procedure combined with a mitral valve operation was performed.
Following the results of Maze III procedure combined with correction of valve disease, disposal of AF was observed in 95% of patients. 46% of patients had stable sinus rhythm to the moment of discharge from the hospital. 24% of patients had atrial rhythm with the maximum heart rate of 80-110 bpm (according to results of 24-hour Holter monitoring). For 25% of patients, it was necessary to implant a pacemaker. According to results of EP study, 13% of these patients suffered from sick sinus syndrome before operation. For 9% of the remaining 12% of patients, the indications for pacemaker implantation were atrioventricular nodal rhythm with low heart rate and pauses more than 3 sec long. For 1% of patients the indication was second degree AV block (type 2) and second degree SA block (type 2); for 1% the indication was complete heart block, and for 1% it was atrial rhythm and pauses more than 3 sec long. 13% of patients with an atrial rhythm and normal heart rate developed typical atrial flutter (AFL) in the early postoperative period. For all of them the RF catheter ablation with linear ablation of the right atrial isthmus and creation of isthmus block was effective, and further recurrence of AFL was not observed.
In the early postoperative period Maze III procedure combined with a mitral valve operation proved to be an effective surgical technique of treatment of persistent and long-standing persistent forms of AF. Only 12% of patients had dysfunction of sinus node work due to iatrogenesis.

BMJ Case Rep
BMJ Case Rep 2016 Dec 1;2016. Epub 2016 Dec 1.
Department of Accident and Emergency, King's College Hospital, London, UK.

A previously well woman aged 63 years presents to the emergency department with vomiting, palpitations and 3 presyncopal episodes. She had no previous medical or cardiac history, with the patient stating that she tried a herbal remedy of boiled comfrey leaves for insomnia 18 hours before arrival to the department. Her ECG showed multiple abnormalities, including bradycardia, second-degree atrioventricular node block, Mobitz Type 2, a shortened QT interval, downsloping ST depression and presence of U waves. Read More

After viewing the images of comfrey and foxglove, it highlighted the possibility of mistaken ingestion of Digitalis, containing the organic forms of cardiac glycosides, such as digoxin and digitoxin. Raised serum digoxin levels confirmed this. The patient was haemodynamically stable, and given digoxin-binding antibodies. After 5 days of cardiac monitoring, her ECG returned to normal rhythm, and she was discharged home.

J Nucl Cardiol
J Nucl Cardiol 2016 Nov 28. Epub 2016 Nov 28.
Division of Cardiovascular Medicine, Department of Internal Medicine and Frankel Cardiovascular Center, University of Michigan, 2nd Floor CVC / SPC 5853, 1500 E. Medical Center Dr.,, Ann Arbor, MI, 48109-5853, USA.
Case Rep Cardiol
Case Rep Cardiol 2016 2;2016:4654031. Epub 2016 Nov 2.
Amrita Institute of Medical Sciences (AIMS), Amrita Vishwa Vidyapeetham University, Kochi, India.
Europace 2016 Nov 6;18(11):1735-1739. Epub 2016 Feb 6.
Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy

Although syncope is the main reason for cardiac pacing in ∼40% of patients affected by atrioventricular block (AVB), very few data are available on the benefit of cardiac pacing in preventing syncopal recurrences.
We retrospectively evaluated 229 consecutive patients (124 males, age 80 ± 10 years) who had received a permanent pacemaker from January 2009 to December 2013 for AVB and syncope (94 patients, 41%) or AVB without syncope (135 patients, 59%). In patients with AVB and syncope, a third-degree or Mobitz II second-degree AVB had been documented in 73 and was only suspected in another 21, all of whom had bundle branch block. Read More

Follow-up was available in 223 patients. At 5 years, the actuarial syncope recurrence rate was 1% (95% CI, 0-3) in patients with documented AVB plus syncope and 3% (95% CI, 1-5) in those without syncope, whereas it was 14% (95% CI, 0-28) in patients with undocumented AVB plus syncope (P = 0.001). The actuarial combined recurrence rate of syncope and/or pre-syncope was 2% (95% CI, 0-4) in patients without syncope, 8% (95% CI, 0-17) in patients with documented AVB plus syncope, and 19% (95% CI, 1-37) in patients with undocumented AVB plus syncope, P = 0.002. All syncopes occurred in patients without overt structural heart disease (SHD), the corresponding actuarial estimate being 4% (95% CI, 0-6) at 1 year and 6% (95% CI, 4-8) at 5 years (P = 0.002 vs. patients with SHD).
Cardiac pacing is highly effective in preventing syncopal recurrences when AVB is documented. Syncope may recur in a non-negligible minority of paced patients when AVB is suspected but not documented and in patients without SHD.

Scand J Med Sci Sports
Scand J Med Sci Sports 2016 Nov 22;26(11):1283-1286. Epub 2015 Dec 22.
Department of Cardiology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia.

Cardiac arrhythmias are commonly reported in freedivers during maximal voluntary breath-holds, but their influence on the cardiological status and their long-term effects on the cardiac health of these athletes have not been investigated. Here we present the results of a study on 32 healthy young men (mean age 32.6 ± 1. Read More

3 years) who were divided into two groups of 16 subjects. One group included 16 continuously training freedivers at the "high achievers in sports" level (DIVERS group). The CONTROL group included 16 healthy young men not involved in sports. The subjects were monitored using 24-h electrocardiogram (ECG), and echocardiological study (EchoCG) for all the subjects was performed. The mean heart rate in the DIVERS group was 69.5 ± 1.7 bpm compared with 70.9 ± 1.5 bpm in the CONTROL group. The minimal heart rate was 42.3 ± 1.0 bpm in the DIVERS group and 48.8 ± 1.7 bpm in the CONTROL group (P < 0.005). The maximal heart rate was 132.8 ± 4.6 bpm in the DIVERS group and 132.1 ± 2.9 bpm in the CONTROL group. ECG analysis revealed supraventricular arrhythmias in the DIVERS group: four of the DIVERS (25%) exhibited supraventricular couplets and triplets, three (19%) exhibited transient first- and second-degree AV blocks (Mobitz type 1) at night, and one (6%) exhibited a second-degree sinoatrial block at night. According to the echocardiogram, the DIVERS had slightly larger left ventricles (5.1 ± 1.33, P < 0.05) and left atriums (41.1 ± 12.7) compared with the CONTROL group without exceeding the normal values. The right ventricle volume (3.6 ± 0.69, P < 0.05) was somewhat above the upper normal value (up to 3.5 cm). In conclusion, freediving athletes exhibited changes in their cardiac status, most likely due to the regular exercise, that were not associated with regular maximal voluntary breath-holds. These changes are within the normal physiological values and do not limit their freediving practice.

J Vet Cardiol
J Vet Cardiol 2016 Oct 6. Epub 2016 Oct 6.
Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Ave., Manhattan, KS 66506, USA.