Dr. Usman's Cardiology Notes

  Post-Ventricular Atrial Refractory Period (PVARP ): • PVARP is a programmable period after a ventricular paced or sensed event in which sensed atrial events do not initiate timing cycles or inhibit atrial pacing. PVARP may prevent the tracking of retrograde atrial events initiated in the ventricle that could trigger PMT in a dual chamber device programmed to a tracking mode. • The initial section of PVARP is the cross-chamber blanking period (composed of absolute refractory and noise window) followed by the fixed refractory period • Events that fall into the absolute refractory window of cross-chamber blanking are not sensed or marked • Events that fall into the noise window are marked as [AS]; there is no noise window for SMART blanking • Events in fixed refractory are marked as (AS), (AF), or (PAC) • Although sensed events in the PVARP fixed refractory window do not initiate timing cycles, they do count toward ATR Entry Counts, AFR, and are included in counters/hi...

Watch the above video and try to calculate RVSP, mean PAP and Diastolic Pulmonary pressure. Formulas: PASP = RVSP (in the absence of RVOT Obstruction or pulmonic stenosis) So RVSP = 4V² + RAP Where V is the peak TR Velocity The mean and end diastolic pressures in the pulmonary artery are directly assessed by measuring peak and end-diastolic velocities of the pulmonary regurgitant (PR) jet Diastolic PA pressure (PAPd) = PR end diastolic pressure gradient + RA pressure Mean PA pressure (PAPm) = PR peak pressure gradient + RA pressure Estimating RA Pressure/CVP: Easiest way to remember the specific RAP value is to understand the normal and high pressure, everything else will fall in the middle category simply! Normal IVC with  normal collapsibility = LOW (3 mmHg) Abnormal IVC with  abnormal collapsibility = HIGH (15 mmHg) Any combination of Abnormal & Normal  values = INTERMEDIATE (8 mmHg) Abnormal IVC, normal collapsibility Abnormalcollapsibility, norm...

  ECG Case: A 71 year old man presented with recurrent episodes of syncope, What are the findings in this EKG, How will you manage? Click the button below to view answer: Show Answer

  Echo Features of Pericardial Tamponade #echocardiography The main echocardiographic findings of pericardial tamponade consist of a pericardial effusion, diastolic right ventricular collapse (high specificity), systolic right atrial collapse (earliest sign), a plethoric inferior vena cava with minimal respiratory variation (high sensitivity), and exaggerated respiratory cycle changes in mitral and tricuspid valve in-flow velocities as a surrogate for pulsus paradoxus. Cardiac tamponade is a life-threatening condition where fluid accumulates in the pericardial space, compressing the heart and impeding its ability to pump blood effectively. Here are the key features of cardiac tamponade and how to assess them on echocardiography: Clinical Features 1. *Hypotension*: Decreased blood pressure due to reduced cardiac output. 2. *Muffled heart sounds*: Distant or muffled heart sounds due to fluid accumulation in the pericardial space. 3. *Distended neck veins*: Increased venous pressure c...

  Can you diagnose what's going on in this ECG strip? So before I go into a diagnosis can I ask what's the atrial rate and what is the ventricular rate? Summary: This is just artifact, as you can see V rate doesnt change ,there is no Apc to trigger a reentrant rhythm like flutter,V rate is not a mutiple of 300 which u would expect if atrial rate was truly 300,termination is without any pause or any suggestion of sinus node overdrive Of All the atrial arrhythmias,  To differentiate between Atrial fibrillation (AF) and  Atrial flutter (AFL) (typical & atypical) are sometimes technically very challenging esp for the non EP , but it’s very important to be able to identify correctly as each of these has a different management strategy, however sometimes even for EP it is not that easy unless EPS is done!  Reason of such complexity especially in case of flutters is because of the so many types of atypical flutters, with so many ecg morphologies !! Any general physician...

ECG Showing Intermittent Delta Wave Above ECG is showing delta wave in some of the QRS complexes, others being normal. To decide further management we take into account various factors. When to Ablate for Pre-excitation / Delta Wave or WPW ECG Pattern or Syndrome: 1. Symptomatic AVRT 2. Pre excited AF 3. Asymptomatic with LV Dysfunction due to electrical dyssnchrony  4. Asymptomatic with High Risk Profession i.e Pilot, Professional Athlete 5. Asymptomatic with High Risk features i.e SPERRI <250 msec (Shortest Pre-excitated RR Interbal) AP ERP <250 msec Multiple APs AP mediated Tachycardia  Low Risk Features: Intermittent Pre-excitation  Delta Wave that disappears on ETT Sudden loss of Delta wave on holter monitoring Ablation is the standard first line treatment for WPW Syndrome in above enlisted scenarios but sometimes it may be delayed or not feasible then following medications can be considered: Structurally Normal Heart: Flecainide, and propafenone  Abnormal...

What is PCSK9?  Our liver makes a protein called proprotein convertase subtilisin/kexin type 9 (PCSK9). PCSK9 regulates how many LDL receptors you have. Studies have shown that if you have naturally high PCSK9, you are more likely to have high cholesterol. PCSK9 inhibitors decrease LDLR degradation by PCSK9, and thereby improve LDL-C clearance and lower plasma LDL-C Here are some landmark trials on PCSK9 inhibitors: Landmark Trials on PCSK9 Inhibitors 1. *FOURIER Trial (2017)*: Evaluated the efficacy and safety of evolocumab (Repatha) in reducing cardiovascular events in patients with established cardiovascular disease. Results showed a 15% reduction in major cardiovascular events. 2. *ODYSSEY OUTCOMES Trial (2018)*: Assessed the efficacy and safety of alirocumab (Praluent) in reducing cardiovascular events in patients with acute coronary syndrome. Results showed a 15% reduction in major cardiovascular events. 3. *SPIRE-1 and SPIRE-2 Trials (2014)*: Evaluated the efficacy and safet...

Here are some of my thoughts on it !  Vagal tone is a measure of the activity of the vagus nerve. vagotonia is a condition where the vagus nerve is excessively excitable! while Hypervagotonia is relatively rarer , which results in sinus node dysfunction and can result in significant symptoms!!  A common misunderstanding among most of us is of autonomics believing that the nerve structures are either sympathetic or parasympathetic!  Hence the commonly used term vagal tone is generally refer to describe the level of activity in the para sympathetic system  Where as in reality the vagus and all the other cardiac nerves carries /contain both sympathetic &parasympathetic components.  Vagal effects  1. Vagal activation simultaneously affects both the sinus and AV nodes.  The resulting ECG can include  sinus slowing / Sinus arrest & varying degrees of AV node block.  2. One of the most commonly seen hallmarks changes of vagally mediate...

  Apical four chamber view of echocardiogram showing Atrial Septal Aneurysm bowing into left and right atria like a swing. As its movement is bi directional, its type 5. Classification of Inter atrial Aneurysm: type 1R: bulging is in the right atrium only type 2L: bulging is in the left atrium only type 3RL: major excursion bulges to the right atrium and the lesser excursion bulges toward the left type 4LR: maximal excursion of the atrial septal aneurysm is toward the left atrium with a lesser excursion toward the right atrium type 5: atrial septal aneurysm movement is bidirectional and equidistant to both atria during the cardiorespiratory cycle. Visit Echo Library>>

In pa­tients with con­gen­i­tal com­plete or high de­gree AVB, pac­ing is rec­om­mend­ed if one of the fol­low­ing risk fac­tors is pre­sent: a) Symp­toms b) Paus­es >3x the cy­cle length of the ven­tric­u­lar es­cape rhythm c) Broad QRS es­cape rhythm d) Pro­longed QT in­ter­val e) Com­plex ven­tric­u­lar ec­topy f) Mean day­time heart rate <50 b.p.m. Reference: ESC Guidelines for Pacing 2021 Thanks 

  Lead­less pace­mak­ers should be con­sid­ered when: no up­per ex­trem­i­ty ve­nous ac­cess ex­ists,  risk of de­vice pock­et in­fec­tion is par­tic­u­lar­ly in­creased, and in  pa­tients on haemodial­y­sis. Watch the above video to get an idea how Leadless Pacemaker looks like on fluoroscopy. Leadless Pacemakers: A Revolutionary Advancement in Cardiac Pacing Leadless pacemakers, also known as self-contained or miniaturized pacemakers, represent a significant breakthrough in cardiac pacing technology. These tiny devices are implanted directly into the heart, eliminating the need for leads, which can often be a source of complications. In this article, we will delve into the world of leadless pacemakers, exploring their design, benefits, implantation procedure, and potential complications. Design and Functionality Leadless pacemakers are small, self-contained devices that combine the pacemaker generator and electrode into a single unit. They are typically 1-2 cm in length...

  Measuring right ventricular systolic pressure (RVSP) on echocardiogram is a crucial assessment for evaluating pulmonary hypertension and right ventricular function. Here's a step-by-step guide on how to measure RVSP on echo: Views and Measurements 1. *Tricuspid Regurgitant Jet*: Obtain a continuous wave Doppler (CWD) tracing of the tricuspid regurgitant jet in the apical 4-chamber view or the right ventricular inflow view. 2. *Peak Velocity*: Measure the peak velocity of the tricuspid regurgitant jet (Vmax) in meters per second (m/s). 3. *Pressure Gradient*: Calculate the pressure gradient across the tricuspid valve using the modified Bernoulli equation: ΔP = 4 × Vmax^2. 4. *Right Atrial Pressure (RAP)*: Estimate the RAP using the inferior vena cava (IVC) diameter and collapsibility. A RAP of 5-10 mmHg is commonly assumed. 5. *RVSP Calculation*: Add the estimated RAP to the pressure gradient to calculate the RVSP: RVSP = ΔP + RAP. Formula RVSP (mmHg) = 4 × Vmax^2 (m/s) + RAP (mmH...

 The Q or the q wave on the surface ecg can sometimes proves very dodgy!!!   So let’s look at the normality or how & why q  is recorded on the surface ecg !!!! Here some of my comments consolidated on this aspect of ecg Normally q is The first or the initial deflection of QRS and results from the rapid depolarisation of the thin walled septum which is occurring from the left to the Right ventricle and this is inscribed in most of the surface ecg leads!!!! B. Normality Small Q are defined as less than 0.03 seconds in duration, or two small squares or less in amplitude & Generally should be no larger than 25% of the associated R. 1. Normality in all leads except V1 through V3, where they are always pathological 2. A Q of any size is generally normal in limb lead III (is varying with respiration) 3. laterally in the chest leads, reflecting left-to-right septal depolarization. 4. A large Q May be seen in lead aVR (as it looks at the endocardial of the heart, it regist...

  Rheumatic mitral stenosis is a serious heart condition that affects millions worldwide. It occurs when the mitral valve, which regulates blood flow between the left atrium and left ventricle, becomes narrowed due to rheumatic fever. This narrowing obstructs blood flow, causing the left atrium to dilate or enlarge. Above Video is showing Rheumatic Mitral Valve Stenosis with dilated LA. Symptoms People with rheumatic mitral stenosis and a dilated left atrium may experience: - Shortness of breath (dyspnea) during physical activity or at rest - Fatigue and weakness - Swelling in the legs, ankles, and feet (edema) - Palpitations or irregular heartbeats - Coughing up blood or pink, frothy mucus Diagnosis Diagnosing rheumatic mitral stenosis involves: - Physical examination and medical history - Echocardiogram (ultrasound of the heart) to visualize the mitral valve and left atrium - Electrocardiogram (ECG) to assess heart rhythm - Chest X-ray to evaluate lung congestion Treatment Treatm...

  ECG Showing Third Degree AV Block   Complete atrioventricular (AV) block, also known as third-degree AV block, is a rare but serious cardiac condition where the electrical signals between the atria and ventricles are completely blocked. This blockage prevents the ventricles from receiving the necessary electrical impulses to contract and pump blood effectively. Causes of Complete AV Block Complete AV block can occur due to various reasons, including: 1. Age-related wear and tear: The AV node can degenerate over time, leading to complete blockage. 2. Cardiac diseases: Conditions like coronary artery disease, cardiomyopathy, and myocarditis can damage the AV node. 3. Infections: Certain infections, such as Lyme disease, can cause inflammation and damage to the AV node. 4. Medications: Certain medications, such as beta-blockers and calcium channel blockers, can slow down or block electrical conduction. 5. Congenital heart defects: Some people are born with AV block due to conge...

This ECG is showing Atrial focus running around 240/min,  two or more ventricular foci competing , seems isorhythmic AV dissociation. So it's sinus tachycardia with Bifascicular block pattern Right Bundle with left axis and p occurs at constant Rate but with ventricular ectopics occurring in bigeminal and trigeminal pattern with no fixed PR interval related hence favoring ventricular ectopic beat with Left ventricular outflow origin. The Ventricular ectopics or ectopies creates lots of concerns , confusion and issue with labelling or terminologies and above all treatment / managment !!!!!  Mostly these are over concerns however sometimes the concern can be very genuine esp in case of them occurring as closely coupled !!! To better identify the Ectopies , the following needed to be known Shortly coupled Ventricular Ectopy (VE) that seems to be lodging onto the preceding T wave (the famous term R on T) May actually be indicative of electrical instability of the heart and de...

LA anatomy on Cardiac CT showing four Pulmonary Veins draining into LA Atrial Fibrillation Cryoablation: Indications 1. Symptomatic paroxysmal or persistent atrial fibrillation (AF) 2. Failed anti-arrhythmic drug therapy 3. Heart failure or reduced left ventricular function Procedure 1. Electrophysiology study (EPS) to identify left-sided pathway 2. Transeptal puncture and transseptal sheath placement 3. Cryoablation catheter (e.g., SL1) placement in left atrium 4. Cryoenergy application to pulmonary veins, posterior wall, and other targeted areas Key Ablation Targets 1. Pulmonary veins (PVs) 2. Posterior left atrial wall 3. Mitral isthmus 4. Left atrial appendage Benefits 1. High success rate for paroxysmal AF 2. Improved symptoms and quality of life 3. Reduced risk of stroke and heart failure hospitalization Risks and Complications 1. Cardiac tamponade 2. Stroke or transient ischemic attack (TIA) 3. Pulmonary vein stenosis 4. Atrio-esophageal fistula (rare) Post-Procedure Care 1. Mon...