scholarly journals Invasive Diagnosis of Coronary Functional Disorders Causing Angina Pectoris

2021 ◽  
Vol 16 ◽  
Author(s):  
Sascha Beck ◽  
Valeria Martínez Pereyra ◽  
Andreas Seitz ◽  
Johanna McChord ◽  
Astrid Hubert ◽  
...  
Keyword(s):  
Angina Pectoris ◽  
Resistance Index ◽  
Diagnostic Procedures ◽  
Functional Disorders ◽  
Drug Induced ◽  
Coronary Vasomotion ◽  
Flow Reserve ◽  
Index Of Microcirculatory Resistance ◽  
Microvascular Spasm ◽  
Microvascular Resistance

Coronary vasomotion disorders represent a frequent cause of angina and/or dyspnoea in patients with non-obstructed coronary arteries. The highly sophisticated interplay of vasodilatation and vasoconstriction can be assessed in an interventional diagnostic procedure. Established parameters characterising adequate vasodilatation are coronary blood flow at rest, and, after drug-induced vasodilation, coronary flow reserve, and microvascular resistance (hyperaemic microvascular resistance, index of microcirculatory resistance). An increased vasoconstrictive potential is diagnosed by provocation testing with acetylcholine or ergonovine. This enables a diagnosis of coronary epicardial and/or microvascular spasm. Ischaemia associated with microvascular spasm can be confirmed by ischaemic ECG changes and the measurement of lactate concentrations in the coronary sinus. Although interventional diagnostic procedures are helpful for determining the mechanism of the angina, which may be the key to successful medical treatment, they are still neither widely accepted nor applied in many medical centres. This article summarises currently well-established invasive methods for the diagnosis of coronary functional disorders causing angina pectoris.

Epicardial coronary stenosis severity and myocardial perfusion

2020 ◽  
pp. 12-16
Keyword(s):  
Myocardial Perfusion ◽  
Myocardial Ischemia ◽  
Coronary Disease ◽  
Myocardial Perfusion Reserve ◽  
Pharmacological Intervention ◽  
Fractional Flow ◽  
Perfusion Reserve ◽  
Flow Reserve ◽  
Stenosis Severity ◽  
Microvascular Resistance

Patients suspected of having epicardial coronary disease are often investigated with noninvasive myocardial ischemia tests to establish a diagnosis and guide management. However, the relationship between myocardial ischemia and coronary stenoses is affected by multiple factors, and there is marked biological variation between patients. The ischemic cascade represents the temporal sequence of pathophysiological events that occur after interruption of myocardial oxygen delivery. The earliest part of the cascade is examined via perfusion imaging, and fractional flow reserve (FFR) is a corresponding index which is specific to the coronary artery. Whereas FFR has come to be regarded a clinical reference standard against which other newer invasive and noninvasive tests are validated, the diagnostic FFR threshold for detecting ischemia was established against a combination of noninvasive ischemia tests that assessed different stages of the ischemic cascade. Moreover, the validity of invasive pressure-derived indices of stenosis severity are contingent on the assumption that pressure is proportional to flow if microvascular resistance is constant, a condition induced by pharmacological intervention or by examining specific segments of the cardiac cycle. Furthermore, myocardial perfusion reserve depends on dynamic modulation of microvascular resistance, and dysfunction of the microvasculature can lead to ischemia even in the absence of epicardial coronary disease.

scholarly journals Safety and effectiveness of drug therapy for the acutely agitated patient (Part I)

2013 ◽  
pp. 127-136
Author(s):  
Gianluca Airoldi
Keyword(s):  
Heart Rate ◽  
Qt Interval ◽  
Physical Restraint ◽  
Safety Data ◽  
Surrogate Marker ◽  
Diagnostic Procedures ◽  
Torsades De Pointes ◽  
Long Qt ◽  
Drug Induced ◽  
Qt Interval Prolongation

Acute agitation occurs in a variety of medical and psychiatric conditions, and the management of agitated, abusive, or violent patients is a common problem in the emergency department. Rapid control of potentially dangerous behaviors by physical restraint and pharmacologic tranquillization is crucial to ensure the safety of the patient and health-care personnel and to allow diagnostic procedures and treatment of the underlying condition. The purpose of this article (the first in a 2-part series) is to review the extensive safety data published on the antipsychotic medications currently available for managing situations of this type, including older neuroleptics like haloperidol, chlorpromazine, and pimozide as well as a number of the newer atypical antipsychotics (olanzapine, risperidone, ziprasidone). Particular attention is focused on the ability of these drugs to lengthen the QT interval in surface electrocardiograms. This adverse effect is of major concern, especially in light of the reported relation between QT interval and the risk of sudden death. In patients with the congenital long-QT syndrome, a long QT interval is associated with a fatal paroxysmal ventricular arrhythmia knownas torsades de pointes. Therefore, careful evaluation of the QT-prolonging properties and arrhythmogenic potential of antipsychotic drugs is urgently needed. Clinical assessment of drug-induced QT-interval prolongation is strictly dependent on the quality of electrocardiographic data and the appropriateness of electrocardiographic analyses. Unfortunately, measurement imprecision and natural variability preclude a simple use of the actually measured QT interval as a surrogate marker of drug-induced proarrhythmia. Because the QT interval changes with heart rate, a rate-corrected QT interval (QTc) is commonly used when evaluating a drug’s effect. In clinical settings, themost widely used formulas for rate-correction are those of Bazett (QTc=QT/RR^0.5) and Fridericia (QTc=QT/RR^0.33), both of which standardize themeasuredQTinterval to an RRinterval of 1 s (heart rate of 60 bpm).However, QT variability can also be influenced by other factors that are more difficult to measure, including body fat, meals, psycho-physical distress, and circadian and seasonal fluctuations.

Abstract 3338: Value of a Novel Index of Microcirculatory Resistance for Invasively Assessing Myocardial Viability After Primary Angioplasty in Acute Myocardial Infarction: Comparison With FDG-PET

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hong-Seok Lim ◽  
Seung-Jea Tahk ◽  
Myeong-Ho Yoon ◽  
Seong-Ill Woo ◽  
Woon-Jung Choi ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Myocardial Viability ◽  
Fdg Pet ◽  
Mean Transit Time ◽  
Area Under The Curve ◽  
Resistance Index ◽  
Primary Pci ◽  
Operating Characteristics ◽  
Fdg Uptake ◽  
Index Of Microcirculatory Resistance

Background: Despite the prognostic importance of the status of coronary microcirculation, there has been lacking in comparative studies on the most reliable invasive measurement for assessing microvascular integrity and myocardial viability in AMI. We compared a novel Index of Microcirculatory Resistance(IMR) to intracoronary wire-based physiologic parameters for evaluating myocardial viability after primary percutaneous coronary intervention(PCI) in AMI. Methods: After successful primary stenting for 28 patients with AMI, Doppler-derived microvascular resistance index (MVRI) and phasic flow velocity patterns were evaluated. Using a pressure-temperature sensor-tipped coronary wire, thermodilution-derived CFR(CFR thermo ) and coronary wedge pressure(P cw ) were measured and the ratio of P cw and mean aortic pressure(P cw /P a ) was calculated, along with IMR, defined as the distal coronary pressure divided by the inverse of the hyperemic mean transit time. 18 F-fluorodeoxyglucose(FDG) PET was performed after primary PCI to evaluate myocardial viability by regional percentage uptake of FDG in infarct-related segments. Results: Among Doppler-derived parameters, regional FDG uptake showed nice correlation with hyperemic averaged peak velocity(r=0.561, p=0.002), hyperemic MVRI (r= −0.452, p=0.016) and baseline deceleration time of diastolic flow velocity (r=0.505, p=0.006). In the group of pressure-derived parameters CFR thermo , P cw /P a and IMR revealed good correlations with regional FDG uptake (r=0.487, p=0.016; r= −0.469, p=0.012; r= −0.656, p<0.001, respectively). By the receiver operating characteristics curve analysis for prediction of myocardial viability, as defined by the 50% FDG-PET threshold value, the largest area under the curve was acquired by IMR and the best cut-off value of IMR for prediction of myocardial viability was 22U (sensitivity of 79%, specificity of 86% and accuracy of 81%). Conclusions: Wire-based coronary physiologic assessment is useful for the prediction of myocardial viability immediately after primary PCI. IMR, a novel index representing the microvascular integrity, is a reliable parameter for the invasive, on-site assessment of myocardial viability after primary PCI in AMI.

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