Sinus arrest primarily affects older patients [1]. It may arise either as a manifestation of sinus node dysfunction, as a side effect from certain drugs used to treat cardiovascular diseases (eg. digitalis), as a complication of myocardial ischemia or sleep apnea, and alongside a fibrotic sinoatrial node condition [2] [3].

Depending on whether the arrest lasts for 2 seconds or for a longer period of time, sinus arrest causes symptoms ranging from mild/unnoticed to severe and life-threatening. Patients diagnosed with the condition usually belong to the senior age group and exhibit various comorbidities. The most common manifestations associated with sinus arrest include syncope, light-headedness, loss of orientation, weakness, angina, and heart failure [4] [5] [6]. Loss of consciousness experienced by a patient due to sinus arrest is known as Adam-Stokes attack. Oliguria may also complicate the clinical picture.

Sinus arrest during periictal period has been observed by a study to frequently arise in patients with inadequately controlled epilepsy [7]. In a typical sinus arrest case, should the electrical activity be paused for too long, different cellular groups will undertake the pacemaking responsibility until the sinoatrial node recovers. If that does not happen, sinus arrest can lead to hypoxia, multiple organ system failure, and cardiac arrest.

• Hypoxemia

  Transient bradycardia in the critical care setting is frequently caused by hypoxemia or oropharyngeal manipulation. [ncbi.nlm.nih.gov]

• Heart Disease

  After 38 s, his heart returned to sinus rhythm at a rate of 140 bpm and he regained consciousness. Vasovagal syncope following exercise in the absence of structural heart disease is uncommonly reported. [ncbi.nlm.nih.gov]

  In our patient, structural heart disease was excluded by transthoracic echocardiography. There were no features in the history to indicate coronary artery disease for which he had minimal risk factors. [casereports.bmj.com]

  Risk factors for SSS include: history of congenital heart disease (even with repairs, the heart is still weak) thyroid disease history sleep apnea disorder coronary artery disease: the coronary artery becomes clogged, and blood flow to the heart is restricted [healthline.com]

• Slow Pulse

  Symptoms of SSS include: fainting or fainting sensations fatigue dizziness palpitations (abnormal heart beats) very slow pulse (bradycardia) difficulty breathing chest pain mental confusion memory problems disrupted sleep It’s important to see your doctor [healthline.com]

• Skipped Beats

  Patients who have sinus pauses may complain of missed or skipped beats, flutters, palpitations, hard beats or may feel faint, dizzy or lightheaded or experience a syncopal episode (passing out). Frequent pauses would heighten these symptoms. [equimedcorp.com]

Sinus arrest is detected via a 12-lead electrocardiogram. Senior individuals who present with symptoms possibly originating from the cardiovascular system, such as angina, loss of consciousness, and fatigue, should always undergo an electrocardiographic evaluation.

A typical sinus arrest electrocardiogram (ECG) will reveal an absence of P waves, with a duration ≥ 2 seconds. Of note, the length of the pause cannot be expressed as a multiple of the basic sinus cycle length. Occasionally and when the P waves are absent for a relatively long time, escape beats appear, as other groups of myocardial cells undertake the pacemaking process for a brief period of time. The R-R interval before and after sinus arrest is stable.

Given that sinus arrest occurs as a result of sinus node dysfunction, myocardial ischemia, certain drugs, and other causes, these need to be investigated as well. Laboratory tests can illustrate a potential hyperkalemia, the ECG will also diagnose ongoing ischemic alterations of the myocardium, and ambulatory or long-term ECG monitoring can also be employed in order to investigate the presence of an underlying pathology and confirm where the symptoms originate from [8].

• P Wave Absent

  This results in an absent PQRST complex. The pause is the same as the distance between two P-P intervals of the underlying rhythm. [ceufast.com]

  QRS: absent 4. P wave: abnormal in size, shape, deflection, or may be hidden in the preceding T wave distorting the T wave contour 5. PR interval: absent 6. Interpretation: Underlying rhythm with Nonconducted PAC XII. Atrial Tachycardia A. [andrews.edu]

In this case report, a patient was presented who had adverse reactions such as nausea, dizziness, insomnia under citalopram treatment, and after his drug was changed to sertraline, developed sinus arrest on the fourth day of treatment. [ncbi.nlm.nih.gov]

The effects of treatment with antibiotics, laser and acupuncture upon chronic maxillary sinusitis in children. Am J Chin Med, 1982;10(1-40):55-8. 23. Yarnell E, Abascal K, Hooper CG. [passeportsante.net]

Prognosis of sinus node dysfunction is mixed; without treatment, mortality is about 2%/yr, primarily resulting from an underlying structural heart disorder. Each year, about 5% of patients develop AF with its risks of heart failure and stroke. [merckmanuals.com]

Treatment and prognosis depend on the cause and cardiac status of the patient. This condition may be drug induced or it may be a result of cardiac disease. [equimedcorp.com]

The long-term prognosis of exercise-induced vasovagal syncope is unclear. [casereports.bmj.com]

After reviewing the literature and discussing possible etiologies for this unusual adverse drug reaction in this setting, we recommend that metoclopramide be used with caution in patients prone to develop bradyarrythmias, particularly those with dysautonomias [ncbi.nlm.nih.gov]

0.11 sec or less Etiology May occur with hypoxia, myocardial ischemia or infarction, hyperkalemia, medications (beta blockers, calcium channel blockers), and increased vagal tone Conduction SA node fails to initiate electrical impulse for one or more [ecgreview.weebly.com]

Etiology of sinus pauses and arrest: alteration in the impulse rate of the P cells. Therefore, the pause length is variable and not necessarily a multiple of the basic sinus rate. [hqmeded-ecg.blogspot.com]

This is further evidence for its etiologic role in intravenous phenytoin toxicity, a phenomenon which is almost always related to infusion rate. The ethanol intravenous diluent fraction may precipitate a reaction in patients taking disulfiram [13]. [jaccr.com]

Only a few epidemiologic studies have been published. [emedicine.medscape.com]

Epidemiology [ edit ] Sick sinus syndrome is a relatively uncommon syndrome in the young and middle-aged population. [en.wikipedia.org]

Epidemiology and burden of nasal congestion. Stewart M, Ferguson B, Fromer L. Int J Gen Med. 2010 Apr 8;3:37-45. 28. De la rhinite allergique aux pathologies sinusiennes (sinusite/polypose) : les liens épidémiologiques et expérimentaux. P. Demoly. [passeportsante.net]

/Richard Parad (US) The arguments for and against a safety net strategy in the NBS protocol - Olaf Sommerburg (DE) Newborn screening in Australia, investigating alternative strategies such as PAP - Enzo Ranieri (AU) 08:30-10:00 Symposium 4 - Beyond Epidemiology [ecfs.eu]

It is therefore suggested that the underlying pathophysiology involved autonomic dysfunction. [ncbi.nlm.nih.gov]

It is therefore suggested that the underlying pathophysiology involved autonomie dysfunction. [nejm.org]

Pathophysiology of isolated systolic hypertension in elderly patients: Doppler echocardiographic insights. [health.usf.edu]

Pathophysiology The sinus node (SN) is a subepicardial structure normally located in the right atrial wall near the superior vena cava entrance on the upper end of the sulcus terminalis. [emedicine.medscape.com]

The episodes of bradycardia did not coincide with orotracheal manipulation, were not prevented by escalating doses of glycopyrrolate, and were not accompanied by AV conduction disturbance as is frequently seen during a transient increase in vagal tone [ncbi.nlm.nih.gov]

Compared to placebo, the drug phenytoin (PHY) has been reported to be significantly more effective in preventing post traumatic seizures during the first 7 days [5]. [jaccr.com]

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