- Long QT Syndrome and Sinus Bradycardia-A Mini Review. [Review]
- FCFront Cardiovasc Med 2018; 5:106
- Congenital long-QT syndrome (LQTS) is an inherited cardiac disorder characterized by the prolongation of ventricular repolarization, susceptibility to Torsades de Pointes (TdP), and a risk for sudden...
Congenital long-QT syndrome (LQTS) is an inherited cardiac disorder characterized by the prolongation of ventricular repolarization, susceptibility to Torsades de Pointes (TdP), and a risk for sudden death. Various types of congenital LQTS exist, all due to specific defects in ion channel-related genes. Interestingly, almost all of the ion channels affected by the various types of LQTS gene mutations are also expressed in the human sinoatrial node (SAN). It is therefore not surprising that LQTS is frequently associated with a change in basal heart rate (HR). However, current data on how the LQTS-associated ion channel defects result in impaired human SAN pacemaker activity are limited. In this mini-review, we provide an overview of known LQTS mutations with effects on HR and the underlying changes in expression and kinetics of ion channels. Sinus bradycardia has been reported in relation to a large number of LQTS mutations. However, the occurrence of both QT prolongation and sinus bradycardia on a family basis is almost completely limited to LQTS types 3 and 4 (LQT3 and Ankyrin-B syndrome, respectively). Furthermore, a clear causative role of this sinus bradycardia in cardiac events seems reserved to mutations underlying LQT3.
- Proposed mechanisms of relative bradycardia. [Journal Article]
- MHMed Hypotheses 2018; 119:63-67
- Relative bradycardia is the term used to describe the mechanism where there is dissociation between pulse and temperature. This finding is important to recognize since it may provide further insights...
Relative bradycardia is the term used to describe the mechanism where there is dissociation between pulse and temperature. This finding is important to recognize since it may provide further insights into the potential underlying causes of disease. There is no known proposed mechanism to explain this phenomenon. We hypothesize that relative bradycardia is the central mechanism reflecting and influenced potentially by the direct pathogenic effect on the sinoatrial node as well as cross-talk between the autonomic nervous system and immune system. Cardiac pacemaker cells may act as a target for inflammatory cytokines leading to alteration in heart rate dynamics or their responsiveness to neurotransmitters during systemic inflammation. These factors account for the important role of how the host response to infectious and non-infectious causes influences the appearance of relative bradycardia. We propose several methods that may be useful to confirm the proposed theoretical framework to further enhance our understanding of this paradoxical phenomenon. This includes measuring, during the episode of relative bradycardia, proinflammatory and anti-inflammatory cytokines, monitoring heart rate variability (HRV), and assessing underlying comorbidities and outcomes in patients with the same disease.
- Long-term follow-up of permanent atrial standstill in a German family with mutation in the SCN5A gene. [Journal Article]
- HCHeartRhythm Case Rep 2018; 4(8):356-358
- Comparison of Intermittent Intravenous Boluses of Phenylephrine and Norepinephrine to Prevent and Treat Spinal-Induced Hypotension in Cesarean Deliveries: Randomized Controlled Trial. [Journal Article]
- A&AAnesth Analg 2018 Aug 14
- CONCLUSIONS: When used as an intermittent bolus regimen to prevent and treat spinal-induced hypotension during CD, NE resulted in a significant reduction in the incidence of bradycardia as compared to an equipotent bolus regimen of PE. We conclude that the hemodynamic profile offered by NE during CD is superior to that of PE due to less fluctuations in HR and possibly cardiac output.
- The Clinical Significance of Relative Bradycardia. [Journal Article]
- WMJWMJ 2018; 117(2):73-78
- CONCLUSIONS: Relative bradycardia is a sensitive but nonspecific clinical sign that may be an important bedside tool for narrowing the differential diagnosis of potential infectious and noninfectious etiologies. Recognizing this relationship may assist the clinician by providing bedside clinical clues into potential etiologies of disease, particularly in the setting of infectious diseases and in circumstances when other stigma of disease is absent.
- Study on Clinical Profile and Predictors of Mortality in Cerbera odollam Poisoning. [Journal Article]
- IJIndian J Crit Care Med 2018; 22(6):431-434
- CONCLUSIONS: C. odollam poisoning is a common method of deliberate self-harm in Kerala. It carries a high mortality rate, and the predictors of mortality include vomiting, bradycardia, hypotension, hyperkalemia, and the presence of severe ECG changes.
- A novel LMNA nonsense mutation causes two distinct phenotypes of cardiomyopathy with high risk of sudden cardiac death in a large five-generation family. [Journal Article]
- EEuropace 2018 Jun 26
- CONCLUSIONS: The novel LMNA nonsense mutation c.544C>T causes a severe arrhythmogenic phenotype manifesting with high incidence of SCD in most patients; and in one sub-family, a distinct phenotype with fast progressing heart failure, indicating the need for early consideration of ICD-implantation and listing for heart-transplantation.
- StatPearls [BOOK]
- BOOKStatPearls Publishing: Treasure Island (FL)
- Kwashiorkor is a disease marked by severe protein malnutrition and bilateral extremity swelling. It usually affects infants and children, most often around the age of weaning through age 5. The disea...
Kwashiorkor is a disease marked by severe protein malnutrition and bilateral extremity swelling. It usually affects infants and children, most often around the age of weaning through age 5. The disease is seen in very severe cases of starvation and poverty-stricken regions worldwide. In the 1950s, it was recognized as a public health crisis by the World Health Organization. However, there was a delay in its recognition, because most cases of childhood death were reported as being from diseases of the digestive system or infectious etiology. Since then, various relief efforts were aimed at eradicating it. As scientists continued to investigate the natural history of the disease in children, they discovered something very striking. Children who were dying from "digestive system diseases" and presenting with diarrhea, cough, coryza, and shortness of breath also were having symptoms of kwashiorkor during this time (pitting edema, anorexia, skin changes, etc.). This finding led to the medical conundrum of whether kwashiorkor was the primary or the secondary cause of death. It was concluded to be the secondary cause of death because many cases of the disease would not have developed without the precipitating stress of diarrhea, dehydration and other infectious diseases such as HIV and measles. While kwashiorkor is a disease of edematous malnutrition, marasmus is similar in appearance. Marasmus is known as the wasting syndrome (malnutrition without edema). Children typically have a depletion of body fat stores, low weight for height, and reduced mid-upper arm circumference. Other features of the disease can include thin, dry skin; a head that appears large relative to the body; an emaciated, weak appearance; bradycardia; hypotension; hypothermia; and thin, shrunken arms, thighs, and buttocks with redundant skin folds.
- Clonidine versus other adjuncts added to local anesthetics for pediatric neuraxial blocks: a systematic review and meta-analysis. [Review]
- JPJ Pain Res 2018; 11:1027-1036
- CONCLUSIONS: Clonidine, compared with other adjuncts, added to local anesthetics for neuraxial block, provides a longer duration of postoperative analgesia with lower incidence of PONV. However, the duration of motor block may also be prolonged by clonidine.
New Search Next
- Competence of general practitioners in requesting and interpreting ECGs - a case vignette study. [Journal Article]
- NHNeth Heart J 2018 Jun 07
- CONCLUSIONS: GPs do not fully adhere to Dutch cardiovascular guidelines on indications for recording ECGs. Diagnostic accuracy was high for atrial fibrillation, sick sinus syndrome and old myocardial infarction and poor for left anterior fascicular block and incomplete right bundle branch block.