Dr. Usman's Cardiology Notes

  Magnesium (MgSO₄) in Emergency and Critical Care: Complete Guide for Clinicians Magnesium sulphate (MgSO₄) is one of the most versatile and lifesaving medications used in emergency medicine, cardiology, and critical care. Despite being inexpensive and widely available, it is often under-utilized or incorrectly dosed. This comprehensive guide covers everything you need to know about its indications, dosing strategies, preparation, mechanisms, side effects, and the clinical scenarios where it truly saves lives. Magnesium plays a central role in neuromuscular stability, cardiac conduction, bronchial smooth muscle relaxation, and cellular enzymatic processes. In acute care settings, timely administration can improve outcomes and even reverse life-threatening arrhythmias. --- What is Magnesium Sulphate (MgSO₄)? Magnesium sulphate heptahydrate is a formulation where 1 gram ≈ 4 mmol of Mg²⁺. In hospital practice, it is commonly stocked as Magnesium sulphate 50% solution, where: 10 ml co...

  Guidelines for Sexual Activity, Air Travel & Driving After Myocardial Infarction (MI) Recovering from a myocardial infarction (MI) is not just about medications and follow-up tests—patients often have important lifestyle questions: When can I resume sexual activity? Is it safe to travel by air? When can I drive again? Clear answers help reduce anxiety, improve adherence, and support safe recovery. Below are evidence-based timelines commonly used in cardiology practice to guide resumption of daily activities after MI, PCI, CABG, or ICD implantation. --- Sexual Activity After MI Sexual activity places a physical demand similar to climbing two flights of stairs. After an MI, the heart needs time to heal before tolerating this exertion. Recommendations: Postpone sexual activity for 4 weeks after MI. Avoid phosphodiesterase-5 inhibitors (Sildenafil) for 6 months, especially if the patient is on nitrates or has unstable symptoms. These precautions minimize the risk of cardiac stres...

  LVOT VTI to Determine Type of Shock A Practical, High-Yield Echocardiography Guide for Clinicians Shock is one of the most time-critical clinical emergencies. While labs and clinical signs are important, echocardiography allows immediate bedside clarification of shock physiology. Among all echo parameters, the LVOT Velocity Time Integral (VTI) is one of the most powerful yet underused tools for identifying the underlying type of shock. Whether you are in the ED, ICU, or cath lab, LVOT VTI is your window into real-time cardiac output. --- What is LVOT VTI? LVOT VTI represents the distance blood travels with each systolic ejection across the left ventricular outflow tract. It is measured using PW Doppler just below the aortic valve. Because: Stroke Volume = LVOT Area × LVOT VTI Cardiac Output = SV × HR A low or high VTI gives immediate insight into flow, cardiac performance, and systemic hemodynamics. --- How to Measure LVOT VTI (Quick Practical Steps) 1. Apical 5-chamber or deep a...

Coronary Microvascular Dysfunction & Vasospastic Angina: The Invisible Heart Enemy Introduction: When Your Heart Speaks, but No Blockage Shows Imagine feeling chest pain, shortness of breath, or fatigue — classic angina symptoms. You go for angiography, expecting to find clogged arteries, but... nothing. The vessels are clean. No major blockages. Yet the discomfort remains. What's happening? This puzzling scenario isn’t rare. Up to 60 % of patients with angina symptoms do not have obstructive coronary artery disease when they undergo angiography.  The culprit? Coronary Microvascular Dysfunction (CMD) and Vasospastic Angina, part of a broader spectrum called INOCA / ANOCA — Ischemia (or Angina) with Non-Obstructive Coronary Arteries. These conditions are often misunderstood, misdiagnosed, or overlooked — but awareness is growing, and it's high time we shine a spotlight on them. --- Why This Topic Matters: The Hidden Side of Heart Disease 1. High Prevalence & Diagnostic B...

At PSAX View Aortic Valve Level : Apply PW Doppler at RVOT to get Acceleration Time. Measure the time it takes to reach peak as shown with white lines To estimate pulmonary artery pressure (PAP) from RVOT acceleration time (AT) on echocardiography, you use the RVOT AT–PASP relationship, which is based on the inverse correlation between AT and pulmonary pressures. --- 📌 How to Measure RVOT Acceleration Time (AT) 1. Use PW Doppler in the RV outflow tract just proximal to the pulmonary valve. 2. Align the Doppler cursor parallel to flow in the RVOT (usually PLAX RVOT or PSAX at the AV level). 3. Measure AT from: Start of systolic flow upstroke → to Peak velocity of the RVOT waveform. This is the RVOT acceleration time (AT). --- 📌 How RVOT AT Estimates Pulmonary Artery Pressure 1. If RVOT AT ≥ 120 ms → Normal PAP A long acceleration time indicates normal pulmonary pressures. --- 2. If RVOT AT < 120 ms → Elevated PAP General Formula for PASP (if no PS or RVOT obstruction): ➡️ PASP ≈ 79...

  🧠 Imagine remembering every single day of your life — with every emotion intact. One teen can.  Meet TL, a teenager in France with hyperthymesia — a rare condition that gives her near-perfect autobiographical memory. She can recall every day of her life in extraordinary detail, from sights and sounds to the emotions she felt. In her mind, these memories are stored in a vivid “white room,” a mental library where every toy, book, and photograph she’s ever owned is neatly organized.  Even painful moments are compartmentalized — her grandfather’s death, for instance, is sealed in a mental chest. But TL’s ability doesn’t stop with the past.  She can also “pre-experience” imagined future events, feeling a strange déjà vu for things that haven’t yet occurred.  Scientists studying her unique mind hope her case will help unlock deeper understanding of how the brain processes memory, imagination, and identity — the essence of what makes us human. Source: 🔹 “Autobiogra...

  🫀 Mechanism of Action of Adenosine – Explained Clearly Adenosine is one of the most fascinating drugs in cardiology — a molecule that literally stops the heart for a moment to save it. Despite its short half-life (less than 10 seconds!), its physiological and therapeutic effects are profound. Let’s break down how this tiny nucleoside exerts such dramatic actions. --- 💊 What is Adenosine? Adenosine is an endogenous purine nucleoside — a naturally occurring compound in the body derived from the breakdown of ATP (adenosine triphosphate). It plays roles in energy transfer, cell signaling, and modulation of cardiac and vascular function. Clinically, adenosine is used mainly for: Termination of paroxysmal supraventricular tachycardia (PSVT) Diagnosis of tachyarrhythmias during electrophysiological testing Assessment of coronary blood flow reserve in stress testing --- ⚙️ Mechanism of Action Adenosine acts through specific adenosine receptors located on cardiac and vascular tissues. T...