Phasic coronary flow characteristics in patients with constrictive pericarditis: comparison with restrictive cardiomyopathy

Constrictive pericarditis and restrictive cardiomyopathy in the modern era

The differentiation between constrictive pericarditis and restrictive cardiomyopathy can be clinically challenging. Pericardial constriction results from scarring and consequent loss of pericardial elasticity leading to impaired ventricular filling. Restrictive cardiomyopathy is characterized by a nondilated rigid ventricle, severe diastolic dysfunction and restrictive filling producing hemodynamic changes, similar to those in constrictive pericarditis. While constrictive pericarditis is usually curable by surgical treatment, restrictive cardiomyopathy requires medical therapy and in appropriate patients, the definitive treatment is cardiac transplantation. Sufficient differences exist between the two conditions to allow noninvasive differentiation, but no single diagnostic tool can be relied upon to make this distinction. Newer echocardiographic techniques such as speckle-track imaging, velocity vector imaging, as well as cardiac computed tomography and cardiac MRI can help differentiate constriction from restriction with high sensitivity and specificity. Outcomes are better with early diagnosis of constriction in particular and early surgical resection.

Diastolic coronary artery compression in a cardiac transplant recipient: Treatment with a stent

Myocardial bridges, with resultant systolic compression of the coronary artery, are common inborn anomalies that generally have a benign course. Diastolic compression of the coronary artery, however, is a rare finding that is believed to be an acquired lesion. It can be hypothesized that during diastole, when left ventricular filling occurs, the coronary artery is compressed against epicardial scar tissue or a noncompliant pericardium. This can then lead to diminished intracoronary blood flow. We present a case of functionally significant diastolic coronary artery compression in a cardiac transplant recipient who was successfully treated with intracoronary stent placement.

[Physiologic evaluation of coronary circulation. Role of invasive and non invasive techniques]

For many years, the evaluation of the extent and severity of coronary artery disease has been mainly anatomical, carried out by coronary angiography. However, this technique has methodological limitations and interobserver variability is considerable. Quantification of coronary reserve with pressure guidewires and intracoronary Doppler now provides more precise physiologic evaluation of coronary circulation. Myocardial perfusion single proton emission computed tomography and echocardiography, combined with stress and/or pharmacological challenge testing, though they are only semiquantitative techniques, also offer appropriate complements to coronary angiography in the functional evaluation of coronary patients. The aim of this paper is to discuss the clinical value of these techniques.

Degos' disease with constrictive pericarditis: a case report

A 47-year-old man with Degos' disease was examined by echocardiography, which showed hypokinesis of the apical left ventricular wall with pericardial effusion. To evaluate the myocardial perfusion and coronary flow reserve, 201Tl scintigraphy and intracoronary Doppler flowmetry were performed. The coronary flow reserve was not decreased nor was there angiographical coronary stenosis, although a pressure study revealed constrictive dysfunction of both ventricles. The constrictive pericarditis might have been induced by pericardial vasculitis, thereby causing the left ventricular wall motion abnormality.

Comparison of electrocardiographic findings in patients with AL (primary) amyloidosis and in familial amyloid polyneuropathy and anginal pain and their relation to histopathologic findings

To assess the prevalence of chest pain and ischemic electrocardiographic (ECG) changes and relate them to histopathologic findings of coronary arteries in cardiac amyloidosis, 33 patients with AL (primary) amyloidosis and 60 patients with familial amyloid polyneuropathy (FAP) were examined. Five patients (15%) with AL amyloidosis had recurrent anginal pain with exertion and 2 of them also experienced anginal pain after orthostatic hypotension. The chest pain was associated with transient downsloping or horizontal ST-segment depression with or without T-wave inversion in right precordial leads, whereas the remaining patients with AL amyloidosis and all patients with FAP did not show anginal pain or ischemic ST-T changes. Histologic sections of coronary arteries were obtained in 12 patients with AL amyloidosis, including 4 of the 5 patients who had angina pectaris and in 25 patients with FAP. Three patients with anginal pain had variable degrees of stenoses of the intramural coronary arteries by amyloid deposition predominantly in the media with normal or nearly normal epicardial arteries. One patient with AL amyloidosis who had effort angina showed marked stenosis and complete occlusion of the small coronary vessels by transmural amyloid deposition. The remaining 8 patients with AL amyloidosis and 25 with FAP without chest pain did not exhibit any stenosis or occlusion of both the epicardial and intramural vessels. These findings suggest that ischemic ST-T changes with chest pain are not so rare in patients with AL amyloidosis, and that markedly decreased myocardial oxygen supply due to diffuse stenotic or occlusive disease of the small coronary vessels by amyloid deposition contributes to the development of clinically significant ischemic heart disease in these patients.

Effect of pericardial pressure on human coronary circulation

A 52-year-old patient underwent percutaneous balloon pericardiotomy because of rapid fluid accumulation. During the procedure, we calculated the amount of blood flow to the nondiseased left anterior descending coronary artery while pericardial pressure was gradually increased by the infusion of warmed normal saline solution. Coronary vasodilator reserve was assessed by intracoronary adenosine. With increasing pericardial pressure, there was a continuous decline in coronary blood flow, due to an increase in coronary vascular resistance, and an unaffected hyperemic response throughout. The maximal hyperemic flow was far less under increased pericardial pressure than at normal pressure, which implies an augmented susceptibility to myocardial ischemia.

Constrictive pericarditis: clinical and pathophysiologic characteristics

Constrictive pericarditis is an uncommon disorder with various causes. Although most often idiopathic, it may also occur after cardiovascular surgery, radiation therapy, and tuberculosis, especially in developing countries. The encasement of the heart by a rigid, nonpliable pericardium results in characteristic pathophysiologic effects, including impaired diastolic filling of the ventricles, exaggerated ventricular interdependence, and dissociation of intracardiac and intrathoracic pressures during respiration. Constrictive pericarditis typically presents with chronic insidious signs and symptoms of predominantly systemic venous congestion. Notoriously difficult to diagnose and distinguish from restrictive cardiomyopathy (RCM), the use of cardiac catheterization, echocardiography (transthoracic and transesophageal), central venous (hepatic and pulmonary) and transvalvular Doppler measurements, and magnetic resonance imaging should secure the diagnosis in most cases, eliminating the need for diagnostic thoracotomy. Although medical treatment may temporarily alleviate symptoms of heart failure, patients do poorly without pericardiectomy.

Contrast-enhanced transthoracic second harmonic echo Doppler with adenosine: a noninvasive, rapid and effective method for coronary flow reserve assessment

OBJECTIVES

The purpose of this study is to evaluate the feasibility in detecting blood flow in the left anterior descending coronary artery (LAD) using transthoracic color Doppler (CD) imaging (in both second harmonic and fundamental mode) along with contrast enhancement and to verify if this new noninvasive method along with adenosine is safe, rapid and effective in assessing coronary flow reserve (CFR).

BACKGROUND

Feasibility of contrast-enhanced transthoracic Doppler recording (in both second harmonic and fundamental mode) of blood flow velocity in the LAD has not been assessed. Adenosine has a greater vasodilator potency and more favorable kinetics than dipyridamole and thus it can be more suitable for assessing CFR in conjunction with this method.

METHODS

Sixty-one patients with angiographically patent LAD underwent CD (both in fundamental and harmonic mode) as well as color-guided pulsed wave (PW) Doppler recording of blood flow velocity in the distal LAD before and after intravenous contrast injection. A second group of patients (n = 77), undergoing coronary angiography, was submitted to transthoracic contrast-enhanced PW Doppler recording of blood flow velocity in the LAD using harmonic CD as a guide, at rest and during adenosine-induced hyperemia.

RESULTS

Harmonic CD along with echo contrast consistently improved blood flow detection in the LAD; the success rate in detecting flow of optimal quality was 88% with this approach, whereas it was 11% and 16% with CD in fundamental mode, respectively, before and after contrast. Pulsed wave Doppler results paralleled those of harmonic CD (p < 0.001 contrast harmonic vs. fundamental). In the second group of patients coronary angiography revealed 0% to <40% stenosis in 24 patients (group I), > or =40% to < or =75% in 17 patients (group II) and >75% stenosis in 34 patients (group III). There was a significant difference in CFR among the three groups of patients; CFR for peak diastolic velocity was (mean +/- SD): 2.88+/-0.7 (group I), 2.09+/-0.5 (group II) and 1.51+/-0.5 cm/s (group II) (p < 0.05 group I vs. both group II and group III; p < 0.05 group II vs. group III). The whole examination took less than 10 min.

CONCLUSIONS

Contrast-enhanced second harmonic Doppler recording of blood velocity in the LAD is highly feasible and in combination with adenosine it is a rapid, safe and effective method for assessing CFR ratio.

Noninvasive assessment of coronary flow velocity and coronary flow velocity reserve in the left anterior descending coronary artery by Doppler echocardiography: comparison with invasive technique

OBJECTIVES

The purpose of this study was to evaluate whether transthoracic Doppler echocardiography (TTDE) can reliably measure coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) in the clinical setting.

BACKGROUND

Coronary flow velocity measurement has provided useful clinical and physiologic information. Advancement in TTDE provides noninvasive measurement of CFV and CFVR in the distal LAD.

METHODS

In 23 patients, CFV in the distal LAD was measured by TTDE (5 or 3.5 MHz) under the guidance of color Doppler flow mapping at the time of Doppler guide wire (DGW) examination. Coronary flow velocity in the distal LAD were measured at baseline and hyperemic conditions (intravenous administration of adenosine 0.14 mg/kg/min) by both TTDE and DGW techniques. Coronary flow velocity reserve was defined as the ratio of peak hyperemic to basal averaged peak velocity in the distal LAD.

RESULTS

Clear envelopes of basal and hyperemic CFV in the distal LAD were obtained in 18 (78%) of 23 study patients by TTDE. There were excellent correlations between TTDE and DGW methods for the measurements of CFV (averaged peak velocity: r=0.97, y=0.94x + 0.40; averaged diastolic peak velocity: r=0.97, y=0.94x + 0.69; systolic peak velocities: r=0.97, y=0.91x + 0.87; diastolic peak velocity: r=0.98, y=0.95x + 1.10). Coronary flow velocity reserve from TTDE correlated highly with those from DGW examinations (r=0.94, y=0.95x + 0.21).

CONCLUSIONS

Noninvasive measurement of CFV and CFVR in the distal LAD using TTDE accurately reflects invasive measurement of CFV and CFVR by DGW method.

Characteristics of coronary flow velocity in constrictive pericarditis

A 50-yr-old man developed constrictive pericarditis following an episode of acute pericarditis. Cardiac catheterization revealed a typical early diastolic dip and plateau configuration in both the right and left ventricular pressure curves. The coronary flow velocity pattern determined using an intracoronary Doppler guidewire showed an abrupt decrease in peak velocity at early diastole and followed by plateau until late diastole, the so-called dip and plateau configuration. After a successful pericardiectomy, cardiac catheterization no longer showed the dip and plateau configuration, but the early diastolic dip in the coronary flow velocity persisted probably because of infiltration of the organic involvement into the myocardium.