Intrinsic frequency method for instantaneous assessment of left ventricular-arterial coupling after transcatheter aortic valve replacement.

BACKGROUND: Aortic stenosis (AS) is the most common cause for valve replacement in the United States. The pathophysiology of AS involves obstruction to the left ventricular (LV) outflow and reduced arterial compliance. The intrinsic frequency (IF) method is a system-based approach for hemodynamic monitoring of the LV-arterial system and involves determination of ω1 and ω2, which represent the dynamics of LV systolic and vascular function, respectively. Total frequency variation of the systemic circulation is the difference between these IFs (Δω = ω1- ω2). OBJECTIVE: Our goal in this study was to investigate whether Δω, obtained from the ascending aortic pressure waveform, can be indicative of LV-arterial coupling after transcatheter aortic valve replacement (TAVR). APPROACH: Thirty patients undergoing elective TAVR for severe, symptomatic AS were included. We applied the IF method to assess the immediate effects of TAVR on LV-arterial coupling. MAIN RESULTS: Mean age was 86 ± 4 years, 50% were male with a mean aortic valve area of 0.7 cm2 and mean ejection fraction (EF) of 59 ± 7%. The results showed a significant decrease in Δω (47.6 to 9.5 bpm, p < 0.00001) and a significant increase in ω2 (51.9 to 84.6 bpm, p < 0.00001) immediately post TAVR. SIGNIFICANCE: These preliminary findings indicate that the IF method can be used to evaluate improvements in LV hemodynamics immediately following TAVR. Use of the IF method may have implications for patients undergoing TAVR with impaired LV systolic function.

Prehospital 12-Lead Electrocardiogram within 60 Minutes Differentiates Proximal versus Nonproximal Left Anterior Descending Artery Myocardial Infarction.

INTRODUCTION: Acute anterior myocardial infarctions caused by proximal left anterior descending (LAD) artery occlusions are associated with a higher morbidity and mortality. Early identification of high-risk patients via the 12-lead electrocardiogram (ECG) could assist physicians and emergency response teams in providing early and aggressive care for patients with anterior ST-elevation myocardial infarctions (STEMI). Approximately 25% of US hospitals have primary percutaneous coronary intervention (PCI) capability for the treatment of acute myocardial infarctions. Given the paucity of hospitals capable of PCI, early identification of more severe myocardial infarction may prompt emergency medical service routing of these patients to PCI-capable hospitals. We sought to determine if the 12 lead ECG is capable of predicting proximal LAD artery occlusions. METHODS: In a retrospective, post-hoc analysis of the Pre-Hospital Administration of Thrombolytic Therapy with Urgent Culprit Artery Revascularization pilot trial, we compared the ECG findings of proximal and nonproximal LAD occlusions for patients who had undergone an ECG within 180 minutes of symptom onset. RESULTS: In this study, 72 patients had anterior STEMIs, with ECGs performed within 180 minutes of symptom onset. In patients who had undergone ECGs within 60 minutes (n = 35), the mean sum of ST elevation (STE) in leads V1 through V6 plus ST depression (STD) in leads II, III, and aVF was 19.2 mm for proximal LAD occlusions and 11.7 mm for nonproximal LAD occlusions (P = 0.007). A sum STE in V1 through V6 plus STD in II, III, and aVF of at least 17.5 mm had a sensitivity of 52.3%, specificity of 92.9%, positive predictive value of 91.7%, and negative predictive value of 56.5% for proximal LAD occlusions. When the ECG was performed more than 60 minutes after symptom onset (n = 37), there was no significant difference in ST-segment deviation between the 2 groups. CONCLUSION: The sum STE (V1-V6) and STD (II, III, aVF) on a 12-lead ECG can be used to predict proximal LAD occlusions if performed within the first hour of symptom onset. This should be considered a high-risk finding and may prompt prehospital direction of such patients to PCI-capable hospitals.

Initial report of percutaneous right ventricular assist for right ventricular shock secondary to right ventricular infarction.

A 57-year-old female suffered an acute inferior ST segment elevation myocardial infarction. The patient failed thrombolysis and was urgently transferred for rescue percutaneous coronary intervention of the right coronary artery. She decompensated after reperfusion of the occluded RCA and developed cardiogenic shock from severe right heart failure refractory to IABP support and maximal pressors. A percutaneous right ventricular assist device was successfully implanted, which improved mean arterial pressure to a viable range and allowed withdrawal of inotropic medications. Right ventricular failure after infarction remains difficult to manage and has a high mortality. Intraaortic balloon pump and LVAD support have not proven beneficial in cardiogenic shock secondary to RV infarction. This is a report of the first insertion of a percutaneous right ventricular assist device for right ventricular support in a human. Further evaluation is warranted to evaluate the potential benefits of such a device as well as optimal timing of initiation of RV support.

Difficult retrieval of the EPI Filterwire with a 5 French FR4 coronary catheter following carotid stenting.

Carotid angioplasty and stenting with an embolic protection device is emerging as a reasonable alternative to carotid endarterectomy in high-risk patients. The deployment and retrieval of these devices, however, can be problematic. We describe a case where a 5 Fr FR4 coronary catheter was used to retrieve an EPI Filterwire device following carotid stenting.

Risk of bleeding complications is not increased in patients undergoing rescue versus primary percutaneous coronary intervention for acute myocardial infarction.

BACKGROUND: Concern for major bleeding complications (MBC) may lead to withholding of anticoagulation and fibrinolytic therapy in preparation for primary percutaneous coronary intervention (PCI), potentially resulting in unacceptable delays in achieving reperfusion. OBJECTIVES: The primary objective of this study was to evaluate MBC associated with primary and rescue PCI and how timing to revascularization affects this variable. METHODS: We evaluated 659 consecutive patients presenting within 24 hours of an acute ST elevation myocardial infarctions (MI). One hundred and eighty-three patients presented for rescue PCI and 476 for primary PCI. Eighty-seven rescue PCI patients were treated within 6 hours of their first dose of fibrinolytic. Demographics, procedural variables, outcomes, and major adverse cardiovascular events (MACE) were compared between the primary and rescue PCI groups and between early and late presenters in the rescue PCI group. RESULTS: We observed that the incidence of MBC was 8% in patients undergoing rescue PCI and 6% in primary PCI (P=0.35). There were no significant differences in bleeding associated with GP IIb/IIIa receptor antagonist use, procedural success, or MACE. Similarly, in patients presenting for early or late rescue PCI there was no significant difference in MBC, procedural success, or MACE. CONCLUSIONS: We concluded that early or late rescue PCI and primary PCI have similar rates of MBC and overall in-hospital outcomes for patients presenting within 24 hours of acute MI. Delaying the timing of a rapid reperfusion strategy in an effort to decrease the incidence of MBC complications is generally not justified.

Intravenous milrinone infusion improves congestive heart failure caused by diastolic dysfunction: a brief case series.

Although there have been significant advances in the medical treatment of heart failure patients with impaired systolic function, very little is known about the diagnosis and treatment of diastolic dysfunction. We report the cases of 3 patients in New York Heart Association functional class IV who had echocardiographically documented diastolic dysfunction as the main cause of heart failure. All 3 patients received medical therapy with long-term milrinone infusion.

Early and aggressive treatment of patients with acute ST segment elevation and non-ST segment elevation myocardial infarction leads to improved clinical outcomes.

Acute myocardial infarction remains a significant burden to our society. Despite being the number 1 cause of mortality, there remains no uniform approach to treatment, which is unlike that of the triage and care of trauma victims. It is now well documented that acute reperfusion therapy has a profound benefit; however, many current strategies take too long to be performed and thus those potential benefits are often reduced. The emergence of prehospital treatment as a means to reducing time to reperfusion provides a new avenue for earlier therapy. With a coordinated aggressive treatment strategy and the identification of primary cardiovascular centers dedicated to the treatment of ST segment elevation myocardial infarctions (STEMI), we believe the mortality of an STEMI can be significantly reduced. Similarly, the treatment of non-ST segment elevation myocardial infarction has shifted to an aggressive approach. Although thrombolytic therapy is not indicated, the use of glycoprotein IIb/IIIa antagonists, as well as early interventional revascularization, is the current preferred treatment strategy. We review important current trials that shape the practice of treatment as well as introduce a novel concept of combined prehospital administration of thrombolytics with urgent culprit artery revascularization.