Strong Memorial Hospital

Introduction: Fibrinolytic therapy with alteplase or tenecteplase (TNK) within 4.5 hours of symptom onset of acute ischemic stroke (AIS) improves functional outcomes and reduces long-term morbidity and mortality, but with increased risk of major bleeding. We sought to compare the safety and efficacy of alteplase and TNK for AIS. Methods: Retrospective, observational, study of adult AIS patients who received alteplase or TNK from May 2020-June 2024. Patients were included if either fibrinolytic was given within 4.5 hours of symptom onset. Extended/wake-up stroke protocol patients were excluded. Primary outcome was incidence of symptomatic ICH (sICH) (National Institutes of Health Stroke Scale [NIHSS] change ≥ 4 and bleeding on computed tomography [CT] scan). Secondary outcomes were occurrence of major and minor bleeding, change in NIHSS score, hospital length of stay (LOS), and in-hospital mortality. Continuous data were analyzed using Mann Whitney U test and categorical data using Chi squared or Fisher’s Exact tests, as appropriate. Results: A total of 479 patients were included; 224 alteplase (46.8%), 255 TNK (53.2%), median age 72 years (IQR 61-83), 53% male. Most patients had minor strokes (55%; NIHSS < 7) and received fibrinolytic in the emergency room (76%). More patients in the TNK group had a large vessel occlusion (26.8% vs. 36.8%). There were numerically more sICH and other major bleeding events in the TNK group; 4.5% vs. 6.7%, p=0.33 and 14.3% vs. 19.2%, p=0.16, respectively, although not statistically significant. There were no differences in minor bleeding events (3.5% vs. 6.7%), change in NIHSS score from admission to discharge (-4 vs -4), hospital LOS (4 days vs. 3 days), or in-hospital mortality (7.8% vs. 7.1%) between alteplase and TNK, respectively. Conclusions: There were no statistically significant differences in safety or efficacy outcomes between alteplase and TNK use for patients with AIS. These results provide real-world experience in a large, older population, with minor stroke. It is possible type II error may be limiting these findings. Additional research is needed to identify patient or stroke related factors that may increase bleeding occurrence and further evaluate if a statistically significant increased risk of bleeding exists with one agent in the real-world AIS population.

Abstract Over the past decade, total neoadjuvant therapy (TNT) has become increasingly accepted and adopted as the initial treatment for locally advanced rectal cancer. Following TNT, treatment response is assessed using three main modalities: clinical exam, endoscopy, and imaging. In this article, we summarize the known advantages, disadvantages, and controversies associated with each method of assessment.

Scenario: A 32-year-old man arrived in the emergency department about 30 minutes after losing consciousness while watching television. He had experienced “racing heart,” dizziness, and breathlessness intermittently in the past 2 to 3 weeks, more intensely in the past week. The patient had gone hiking in the White Mountains in New Hampshire about 2 months earlier, where he developed a red rash on his left thigh. After returning from that trip, he developed a headache, muscle aches, and low-grade fever with chills, which he attributed to the flu. He did not seek medical attention and felt better a week after having taken an over-the-counter pain and fever medication. He had no history of joint pain or facial asymmetry or weakness. Vital signs on arrival: body temperature 36.5 ºC (97.6 ºF), pulse rate 40/min and regular, blood pressure 108/59 mm Hg. Cannon A waves were seen on the jugular venous pulse examination. No skin rash was noted. An initial electrocardiographic (ECG) rhythm strip in lead II provided by emergency medical services is shown below.Third-degree (complete) heart block with a junctional escape rhythm of 40 beats per minute.Normally, the electrical impulse generated by the sino atrial (SA) node in the right atrium spreads to both atria and reaches the atrioventricular (AV) node, where it is delayed, allowing adequate ventricular filling. The impulse is then routed through a specialized conducting system of intraventricular conduction pathways, which include a bundle of His, right and left bundle branches, and fibers of Purkinje cells. An AV block occurs when this impulse propagation is slowed or interrupted anywhere in this pathway.The severity of the AV block ranges from first degree (all impulses are conducted from atria to ventricles albeit with a delay) to second degree (some impulses are not conducted) to complete or third-degree block (no impulses are conducted). The AV node and His-Purkinje cells have intrinsic automaticity but are normally suppressed by the SA node owing to their higher firing rate. However, when the impulse from the SA node is blocked, a conduction disturbance occurs, allowing escape rhythms to emerge from the more distant pacemakers. A complete heart block is an example of an AV dissociation where the ventricular rate is slower than the atrial rate. As no impulse is conducted from the atria to the ventricles, the latter must be paced by escape rhythms at or below the AV node. An escape rhythm that arises from the AV node (junctional) usually generates a ventricular rate of 40/min to 60/min with a narrow QRS complex (seen in this case) as the impulse traverses the usual conduction pathway. Conversely, a block distal to the AV node generates a ventricular escape rhythm with slower rates of 20/min to 40/min and a wide QRS complex. The P-wave morphology appears different when it overlaps with the T wave. Given the irregular rhythm, there is a potential for a wandering atrial pacemaker, though confirmation would require additional leads and/or prolonged ECG recording to assess the atrial activity fully.Atrioventricular block can be caused by increased vagal tone and several pathologic conditions. Given that this young adult patient had no cardiac history and experienced a rash, headache, fever, and muscle aches shortly after traveling to a Lyme-endemic area and developing syncope, his acute symptoms are most likely due to Lyme disease. Lyme disease is a tick-borne infection most commonly caused by Borrelia burgdorferi. The symptoms of Lyme carditis, seen in 4% to 10% of all patients, are caused by transmural inflammation of the heart muscle, leading to AV conduction and other cardiac abnormalities.After ensuring the patient’s hemodynamic stability, the nurse should obtain a 12-lead ECG (given that only a single-lead ECG was initially available) to confirm the diagnosis and assess for other potential cardiac abnormalities. Pending serologic confirmation of Lyme disease, empirical treatment with intravenous antibiotics was initiated, and a cardiologist was consulted for the AV block. The severity of AV block in Lyme carditis can fluctuate rapidly in a short period. As this patient presented with syncope and complete heart block, a temporary pacemaker may be indicated. Close monitoring and continuous ECG are warranted.

•Early aortic valve replacement before the development of severe symptomatic aortic stenosis is not associated with a benefit for most hard endpoints including mortality and myocardial infarction but is associated with a benefit in stroke.•The mechanism for the potential benefit of early aortic valve replacement on stroke remains unclear.•Younger patients and women may derive a mortality benefit from early aortic valve replacement, but this warrants further study.

Scenario: Below is a 12-lead electrocardiogram (ECG) of an 80-year-old unresponsive man obtained by paramedics en route from the patient’s home to the emergency department. It was unclear how long the patient had been unconscious, but distal pulses were intact. He required respiratory support with a bag valve mask. Per a family member, his history included prior myocardial infarction (MI) with coronary artery bypass graft surgery, heart failure, and an implantable cardioverter defibrillator (ICD) placed a “few years ago.” He remained unresponsive except for localized pain upon arrival at the emergency department and was intubated. What is the underlying mechanism of the QRS complexes?Ventricular paced rhythm at a rate of 40 bpm.In this scenario, the myocardial conduction cells fail to generate automatic, or intrinsic, electrical impulses; thus, the ICD initiated ventricular pacing to support cardiac output, but at a slow ventricular rate. Unfortunately, the ICD did not include atrial pacing; hence, atrial “kick” has been lost. The QRS complexes in all ECG leads are wide (ie, prolonged in duration), which is expected with ventricular paced rhythms because the pacing impulse travels across the ventricles more slowly outside the normal His-Purkinje conduction network. The wide QRS and dominant S wave in V1 are due to the initial depolarization in the right ventricle (location of pacer wire) that then spreads to the left ventricle. This morphology should not be confused with left bundle branch block, or a ventricular escape rhythm. Concomitant prior MI and heart failure in this patient may have also affected the myocardium, which may delay ventricular depolarization even more. Finally, although the ventricular paced rhythm may confound the ST segment in V3 and V4, acute MI should be considered given this patient’s history and unstable condition.Chart review indicated that this patient had been followed by a cardiologist for his ischemic heart failure with an ejection fraction of 39%. Current practice guidelines recommend an ICD to prevent sudden cardiac death due to life-threatening ventricular tachycardia and ventricular fibrillation in patients with ischemic cardiomyopathy and severe heart failure with reduced ejection fraction. This patient received an ICD without any significant events until this event at home. Generally, ICDs provide cardioversion (synchronized) or defibrillation (unsynchronized) and pacing support. In some cases, severe bradycardia following an ICD shock may occur with subsequent ventricular pacing support to maintain cardiac output.Initially the exact mechanism of this patient’s unresponsive episode was unclear; thus, the ICD was interrogated to determine the potential cause. This assessment would also help determine if the ICD was functioning properly. Concurrently, other diagnostic evaluation is indicated to rule out other potential causes (eg, acute myocardial ischemia, electrolyte depletion, toxins). Subsequent interrogation of the patient’s ICD showed that he had 3 episodes of ventricular fibrillation ~2 hours before this event, prompting his ICD to appropriately deliver multiple discharges. His first 2 troponin test results were negative for acute MI, with nonsignificant delta troponin. After stabilization, the patient regained consciousness 5 hours after arrival in the emergency department. However, several hours later, he developed significant ST-segment depression in multiple ECG leads, with a positive third troponin test result. He was taken urgently for percutaneous coronary intervention of the ungrafted distal left anterior descending coronary artery. Remarkably, he was discharged home after 8 days.