These are electrical impulses that cause individual muscle fibers to contract. All muscle contraction, whether cardiac, skeletal, or smooth, depends upon action potentials. Sinus rhythm describes the normal electrical activity of the heart that allows the heart muscle to contract (myocardial contraction). You should think of the SAN as an area of specialized pacemaker cells. The sinoatrial node is not an easy to distinguish structure – it looks the same as any other area inside the heart – and the only differences are seen under extreme magnification.
![junctional escape rhythm junctional escape rhythm](https://ecgcourse.com/wp-content/uploads/2017/03/Rhythm-B-Q2.jpg)
The location of the sinoatrial node or SAN is at the top of the right atrium in an area of tissue called the triangle of Koch. This is why your heart beats faster when exercising. When the heart slows the soldiers probably won’t reach their destination on time the heart might not receive enough oxygen. If the drum beats quickly the soldiers make a lot of ground – the heart pumps as much oxygen around the body as it can. What does a pacemaker do? It’s a good idea to imagine an army drum that tells soldiers when to take a step. In a healthy heart, the sinoatrial node (SAN) is the default pacemaker.
![junctional escape rhythm junctional escape rhythm](https://image.slidesharecdn.com/6aventricularrhtyhms-110624075154-phpapp02/95/ventricular-rhythms-bmhtele-21-728.jpg)
How slowly, rapidly, or efficiently our hearts contract is integral to our overall levels of health. You will probably have come across the image below before – the famous circulatory system that sends nutrient and oxygen-rich blood into our tissues or collects waste products and sends them to the liver and urinary system. This forces blood to be pumped through the chambers and into the lungs or the rest of the body.
![junctional escape rhythm junctional escape rhythm](https://i2.wp.com/www.stemlynsblog.org/wp-content/uploads/2018/11/Screenshot-2018-11-03-16.55.00.png)
In which order these muscles contract is extremely important – from the top to the bottom of the atria, a tiny pause, and then across the ventricles.
![junctional escape rhythm junctional escape rhythm](https://litfl.com/wp-content/uploads/2018/08/Digoxin-toxicity-Regularised-atrial-fibrillation-AF.jpg)
Junctional rhythm and sinus rhythm have almost the same result – both types send electrical impulses through specialized heart muscle ( cardiac muscle) to force certain areas of the heart to contract at certain times. Absent P wave – junctional rhythm Junctional Rhythm vs Sinus Rhythm If the SAN fails to fire, an area located at the meeting point of the atria and ventricles (atrioventricular junction) takes over the role of pacemaker, causing junctional rhythm. Heart rhythm is the result of electrical impulses sent from the pacemaker cells of the sinoatrial node (SAN) at the top of the right atrium. STRUCTURAL NODAL DISEASE OCCURS IN 5% OF ALL CASES OF MI AND MORE THAN 50% OF AIMI (LCA&RCA) THE PRESENCE OF STRUCTURAL NODAL DISEASE CAN BE DIFFERENTIATED FROM EXTRINSIC CAUSES BY VAGOLYTIC AND SYMPATHOMIMETIC MANOEUVRES AND OVER DRIVE SUPPRESSION ATROPINE (1-2mg) ADMINISTRATION SHOULD INCREASE THE SINUS RATE TO MORE THAN 90 TREATMENT USUALLY REQUIRES DEMAND PACE MAKERS ĪPPROACH TO BRADYARRYTHMIAS BRADYCARDIA HR<60 MAINTAIN PATENT AIRWAY ASSIST BREATHING GIVE O2 MONITOR ECG,BP,OXIMETRY ESTABLISH IV ACCESS SIGNS & SYMPTOMS OF POOR PERFUSION NO YES OBSERVATION *PREPARE FOF TRANSCUTANEOUS PACING ,USE WITHOUT DELAY FOR HIGH DEGREE BLOCK(TYPE 2nd&3 rd DEGREE AV BLOCK) *CONSIDER ATROPINE 0.Junctional rhythm describes a heart-pacing fault where the electrical activity that initiates heart muscle contraction starts in the wrong region. SICK SINUS SYNDROME SSS IS A PAN CONDUCTION DEFECT POSSIBLY INVOLVING THE ENTIRE CONDUCTING SYSTEM INCIDENCE EQUAL IN MALE & FEMALE MORE THAN 1/2 THE CASES OCCUR>50 YEARS OF AGE SSS PRESENTS AS 1.SINUS BRADYCARDIA 2.BRADYCARDIA TACHYCARDIA SYNDROME 3.BRADYCARDIA WITH SA OR AV BLOCK OR ESCAPE RYTHM, OR HEMIBLOCK OR AF OR INTRA ATRIAL BLOCK 4.SINUS PAUSE/ARREST 5.INADEQUATE SINUS TACHYCARDIA 6.UNCOMPLICATED ESCAPE RHYTHM SEC TO MARKED SA DEPRESSION 7.PROLONGED RETURN CYCLE FOLLOWING PREMATURE DISCHARGE OF THE SA PACE MAKER Eg…ATRIAL, /VENTRICULAR EXTRA SYSTOLE OR RETROGRADELY CONDUCTED JUNCTIONAL BEAT SINUS BRADYCARDIA OR SLOW AV JUNCTIONAL RHYTHM AT THE TIME OF SYMPTOMS IS ENOUGH FOR DIAGNOSIS Junctional beat without retrograde conduction Junctional beat with retrograde conduction ( p wave superimposed on QRS complex) Prolonged return cycle following retrogradely conducted junctional beatĭIAGNOSIS Junctional escape rhythm possible sinus node dysfunction DIFFERENTIAL DIAGNOSIS A) SICK SINUS SYNDROME B) CAD (ACUTE OR CHRONIC) C) CARDIOMYOPATHY D) INFLAMMATORY E) IATROGENIC ECG OF THE WEEK Prof Dr.S.TITO’s UNIT M5 Dr.G.ArunkumarĤ6 year old male a known smoker and diabetic presented with recurrent episodes of giddiness O/E General exam- normal PR- 50/min irregularly irregular BP-100/70 mm Hg Systemic examination- no abnormalities ECG was taken Ī standard 12 lead ECG showing Heart rate 40/min Sinus Arrest Junctional rhythm Irregularly irregular Varying RR interval Q waves in II III avf QTc interval 352 ms QRS axis 60 degree HEART RATE AFTER ATROPINE ADMINISTRATION WAS 70/MIN