Dr. Usman's Cardiology Notes

Temporary Pacemaker (TPM) Lead Settings and Troubleshooting: A Practical Guide Temporary pacemakers (TPMs) are commonly used for patients with symptomatic bradycardia, high-grade AV block, sinus node dysfunction, post-cardiac surgery conduction disturbances, acute myocardial infarction, drug-induced bradyarrhythmias, and during electrophysiology procedures. Safe temporary pacing requires an understanding of the pacing rate, output, sensitivity, capture threshold, sensing threshold, pacing mode, and lead integrity. This article provides a practical approach to temporary pacemaker lead settings, threshold testing, and troubleshooting. 1. Basic Components of a Temporary Pacemaker System A temporary pacing system consists of: Temporary pacing lead External pulse generator Connecting cable Battery/power source ECG and haemodynamic monitoring The pacing lead has two major functions: Pacing: delivering an electrical stimulus to the myocardium. Sensing: detecting intrin...

  2026 AHA/ACC Guideline for Preoperative Cardiovascular Risk Assessment Before Noncardiac Surgery The 2026 AHA/ACC Guideline for Perioperative Cardiovascular Management of Patients Undergoing Noncardiac Surgery provides a structured, stepwise approach to evaluating cardiovascular risk before surgery. Importantly, the 2026 guideline is a reaffirmation of the 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM guideline. After reviewing evidence published during the preceding two years, the ACC/AHA Joint Committee concluded in September 2026 that the 2024 recommendations remain valid and current. The recommendations and supporting material are unchanged. The central principle is simple: preoperative cardiovascular assessment should identify patients who may benefit from optimization or additional testing without unnecessarily delaying surgery or exposing patients to low-value investigations. 1. Goals of Preoperative Cardiovascular Assessment The purpose of preoperative cardiovascular evalua...

The 2026 ESC Guidelines for the Management of Heart Failure, published on 28 August 2026, have substantially changed the terminology and treatment framework compared with the 2016 guideline. In particular, HFmrEF has been removed, and HFrEF now includes patients with LVEF <50%.  2026 ESC Guidelines for the Diagnosis and Management of Heart Failure With Reduced Ejection Fraction The 2026 European Society of Cardiology (ESC) Guidelines for the Management of Heart Failure introduce important changes in the definition, classification, diagnosis and treatment of heart failure. Published in August 2026, the guideline simplifies the traditional heart-failure phenotype classification, introduces stages of heart failure from A to D, and establishes a new framework for pharmacological and interventional treatment. One of the most important changes is the redefinition of heart failure with reduced ejection fraction (HFrEF). The previous distinction between HFrEF and HFmrEF has been removed...

Recommendations for Patients With Preserved LVEF (≥50%): A Practical Guide to HFpEF Treatment Heart failure with preserved ejection fraction (HFpEF) is an increasingly recognized form of heart failure in which patients have symptoms and signs of heart failure despite a relatively preserved left ventricular ejection fraction. According to the 2022 AHA/ACC/HFSA Heart Failure Guideline, HFpEF is defined as heart failure with an LVEF ≥50% together with evidence supporting increased left ventricular filling pressures.  Unlike HFrEF, where several therapies have established mortality benefits, treatment of HFpEF has historically focused on controlling congestion, blood pressure, atrial fibrillation, ischemic heart disease and other associated conditions. However, the therapeutic landscape has changed substantially, particularly with the introduction of SGLT2 inhibitors. The 2022 AHA/ACC/HFSA guideline provides a practical framework for the treatment of symptomatic patients with HFpEF. TR...

  Heart Blocks on ECG: A Practical Guide to First-, Second- and Third-Degree AV Block Atrioventricular (AV) block is one of the most important conduction abnormalities encountered on ECG. Correctly identifying the pattern—particularly distinguishing Mobitz I from Mobitz II—has major implications for prognosis, monitoring and pacemaker therapy. The key is to systematically assess the relationship between P waves, PR intervals and QRS complexes. --- 1. What is AV Block? AV block occurs when conduction of electrical impulses from the atria to the ventricles is delayed or interrupted at the AV node, His bundle or Purkinje system. It is broadly classified as: 1. First-degree AV block 2. Second-degree AV block Mobitz I / Wenckebach Mobitz II 2:1 AV block High-grade/advanced AV block 3. Third-degree AV block / complete heart block The ECG diagnosis depends primarily on identifying: P-wave behavior → PR interval → conducted/dropped QRS complexes → atrial–ventricular relationship. --- 2. Fi...