PubMed Health⌕ Search

Biomedical subjects

K B Kisslo

Publications and source records attributed to K B Kisslo.

At least 37 records · Page 2Linked to original sources
PubMed1992

Influence of mitral valve morphology on mitral balloon commissurotomy: immediate and six-month results from the NHLBI Balloon Valvuloplasty Registry.

Echocardiographic data were analyzed in 555 patients undergoing mitral balloon commissurotomy (MBC). Patients were enrolled in the National Heart, Lung, and Blood Institute Balloon Valvuloplasty Registry from 24 centers. There were 456 women and 99 men with a mean age of 54 years. Before MBC the two-dimensional echocardiographic variables of mitral valve thickness, mobility, calcification, and subvalvular disease were evaluated and assigned scores of 1 to 4. The mitral valve morphology score was related to mitral valve area (MVA) measured after MBC by cardiac catheterization. The leaflet mobility score was related to the immediate post-MBC MVA: 2.2 +/- 0.8 cm2 for grade 1, 1.9 +/- 0.7 cm2 for grade 2, 1.7 +/- 0.7 cm2 for grade 3, and 1.9 +/- 0.9 cm2 for grade 4 (p less than 0.001). Results of the MVA after MBC showed a similar relationship for each echocardiographic variable. The total morphology score (sum of the four variables) showed a weak relationship to MVA immediately after MBC (r = 0.24), which was persistent at 6 months after MBC (r = -0.25). Multiple regression analysis showed that the MVA after MBC is predicted by pre-MBC MVA (p less than 0.001), left atrial size (p = 0.01), balloon diameter (p = 0.02), cardiac output (p = 0.004), and leaflet mobility (p = 0.01). The R2 of the model was 0.31 (p less than 0.001). Total morphology score, leaflet thickness, calcification, and subvalvular disease were not important univariate or multivariate predictors of the results of MBC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mechanisms of balloon angioplasty and directional coronary atherectomy as assessed by intracoronary ultrasound.

OBJECTIVE: This study was designed to use intracoronary ultrasound imaging to elucidate the physical effects of balloon angioplasty and directional coronary atherectomy in vivo in humans. BACKGROUND: The proposed mechanisms of coronary artery interventions such as balloon angioplasty and directional atherectomy are based on animal studies or pathologic findings and these data may not be applicable to living patients. Intracoronary ultrasound findings correlate highly with pathologic results and may allow in vivo assessment of the mechanisms of such interventions in humans. METHODS: Intracoronary ultrasound imaging was performed in 45 patients after a successful coronary intervention (balloon angioplasty in 30, directional coronary atherectomy in 15). Ultrasound images obtained at the treatment site and at an adjacent angiographically normal references site were analyzed quantitatively for minimal lumen diameter, cross-sectional lumen area, are enclosed by the internal elastic lamina, plaque area (internal elastic lamina area--lumen area) and percent area stenosis (plaque area/internal elastic lamina area). Qualitative analysis included assessment of presence of dissection, plaque composition and plaque topography. RESULTS: The results of the two procedures were similar with respect to minimal lumen diameter (angioplasty 2.6 +/- 0.5 vs. atherectomy 2.6 +/- 0.3 mm, p = NS), lumen area (0.07 +/- 0.03 vs. 0.07 +/- 0.02 cm2, p = NS) and percent area stenosis (59 +/- 14% vs. 51 +/- 21%, p = NS). However, after angioplasty, the internal elastic lamina area was significantly larger at the treated site than at the reference site (delta = +0.03 +/- 0.04 cm2, p = 0.01). There was no significant difference between the two sites after atherectomy (delta = -0.01 +/- 0.05 cm2, p = NS). In addition, dissection was seen significantly more often after balloon angioplasty than after atherectomy (50% vs. 7%, p less than 0.01). The results were similar when stratified for plaque composition and morphology. These data were confirmed in six additional patients who underwent ultrasound imaging before and after the intervention. CONCLUSIONS: Thus, the improvement in lumen dimensions after coronary balloon angioplasty is a result of both vessel stretch, demonstrated by a larger internal elastic lamina area at the treated site, and dissection. Both vessel stretch and dissection are uncommon after atherectomy, a finding consistent with plaque removal as the major mechanism for improved lumen area after this procedure.

Adult↗
PubMed1992

Comparison of preload recruitable stroke work, end-systolic pressure-volume and dP/dtmax-end-diastolic volume relations as indexes of left ventricular contractile performance in patients undergoing routine cardiac catheterization.

The end-systolic pressure-volume relation, the relation between stroke work and end-diastolic volume, termed the preload recruitable stroke work relation, and the relation between the peak of the first derivative of left ventricular pressure (dP/dtmax) and end-diastolic volume have been employed as linear indexes of left ventricular contractile performance in laboratory animals. The purpose of this study was to examine the relative utility of these indexes during routine cardiac catheterization in seven human subjects (mean age 48 +/- 18 [SD] years) with a normal left ventriculogram and coronary angiogram. Left ventricular pressure was recorded continuously with a micromanometer catheter, and left ventricular volume was derived from digital subtraction contrast ventriculograms obtained at 30-ms intervals. Transient occlusion of the inferior vena cava with a balloon-tipped catheter was employed to obtain beat to beat reductions in left ventricular pressure and volume over 8.7 +/- 1.7 cardiac cycles. Stroke work declined by 49 +/- 13% during vena caval occlusion, but end-systolic pressure fell by only 26 +/- 11%, and changes in dP/dtmax were small and inconsistent (12 +/- 22%). Consequently, the range of data available for determination of the preload recruitable stroke work relation greatly exceeded that for the end-systolic pressure-volume relation and the dP/dtmax-end-diastolic volume relation, and much less linear extrapolation from the measured data was required to determine the volume-axis intercept. Preload recruitable stroke work relations were highly linear (r = 0.95 +/- 0.07), and much more so than end-systolic pressure-volume relations (r = 0.79 +/- 0.23).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography, Digital Subtraction↗
PubMed1992

Critical mitral stenosis causing ischemic hepatic failure. Successful treatment by percutaneous balloon mitral valvotomy.

We report a 52-year-old patient with severe mitral stenosis who developed new onset atrial fibrillation, low output congestive heart failure and fulminant ischemic hepatic failure with subsequent severe coagulopathy. Percutaneous mitral valvotomy resulted in dramatic clinical improvement with complete resolution of liver function. This case illustrates the potential life-saving role for percutaneous balloon mitral valvotomy in treating critically ill patients who are unable to undergo thoracotomy due to coexisting medical illness.

Atrial Fibrillation↗
PubMed1991

Doppler echocardiographic findings in adults with severe symptomatic valvular aortic stenosis. Balloon Valvuloplasty Registry Echocardiographers.

Baseline echocardiographic data in 680 adults (mean age 78 years) undergoing balloon aortic valvuloplasty at 24 medical centers were analyzed to describe the degree of outflow obstruction in patients with symptomatic aortic stenosis. Maximal aortic jet velocity ranged from 2.3 to 6.6 m/s (mean 4.4 +/- 0.8) and continuity equation valve area ranged from 0.1 to 1.4 cm2 (mean 0.6 +/- 0.2). Of note, 36% had a jet velocity less than or equal to 4.0 m/s but only 3% had a valve area greater than 1.0 cm2 due to a high prevalence of impaired systolic function (54%). Outflow tract diameter was poorly correlated with body surface area (p = 0.26), although the group mean diameter was smaller in women than in men (1.9 +/- 0.2 vs 2.1 +/- 0.3 cm, p = 0.0001). Mean pressure gradient was related closely to maximal gradient (r = 0.92) and to maximal jet velocity (mean delta P = 2.4 V2 + 0.75 mm Hg). Simpler measures of aortic stenosis severity were correlated with Doppler and invasive valve area as follows: maximal jet velocity (r = -0.36 and -0.32), mean gradient (r = -0.33 and -0.29), outflow tract to jet velocity ratio (r = 0.67 and 0.40), and the fractional shortening velocity ratio (r = 0.29 and 0.22). This study demonstrates marked variability in stenosis severity in symptomatic adults referred for balloon aortic valvuloplasty. The absence of a predictable relation between outflow tract diameter and body size emphasizes the importance of this measurement in each patient if definition of valve area is needed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Intracoronary ultrasound evaluation of interventional technologies.

The feasibility and applicability of intravascular ultrasound (IVUS) of the coronary arteries were evaluated in 65 patients undergoing 70 coronary interventional procedures. Morphologic and quantitative analyses were performed with a mechanically rotated IVUS catheter (4.8Fr, 20 MHz) and with orthogonal view cineangiography. A semiautomated edge-detection algorithm was used for cineangiographic quantification. Coronary interventions included 45 percutaneous transluminal coronary angioplasties, 9 excimer lasers, 11 directional coronary atherectomies, 3 rotational atherectomies and 2 stents. Most lesions consisted of a mixture of plaque composition (hard, n = 30; soft, n = 64). Other unique morphologic data by IVUS were plaque topography (eccentric, n = 34; concentric, n = 36) and vessel dissection (IVUS [n = 29] versus angiography [n = 14], p less than 0.05). Postprocedure minimal lumen diameter and cross-sectional area measured by IVUS were larger and poorly correlated with angiography (r = 0.28, standard error of the estimate = 0.52 mm; r = 0.08, standard error of the estimate = 1.0 cm2, respectively). IVUS is more sensitive than angiography when assessing postintervention lesion characteristics including vessel dissection and plaque morphology. Catheter-based ultrasound appears to be a useful adjunct to contrast angiography when evaluating and comparing the therapeutic impact of conventional percutaneous transluminal coronary angioplasty with new technologies.

Algorithms↗
PubMed1991

Intravascular ultrasound assessment of the renal artery.

OBJECTIVE: To determine the feasibility and diagnostic value of catheter-based intravascular ultrasound imaging compared with angiography for visualizing renal artery structure. DESIGN: Renal artery images were obtained in patients with renal artery stenosis having percutaneous balloon angioplasty and in normal subjects by digital angiography and by a 20-MHz, mechanically driven, catheter-based, intravascular ultrasound imaging system. SETTING: A referral-based university hospital. PATIENTS: Four randomly selected normal subjects without known renal disease and four consecutive patients with known renal artery stenosis referred for percutaneous balloon angioplasty. INTERVENTIONS: Digital angiograms and intravascular ultrasound images of nine renal artery segments were obtained. In patients with renal artery stenosis, imaging was done before and after balloon angioplasty. MAIN RESULTS: Digital angiography and ultrasonography correlated closely in the determination of arterial lumen diameter (r = 0.81) and cross-sectional area (r = 0.83). However, ultrasonography provided structural information not shown by angiography. All normal arteries showed discrete intimal, medial, and adventitial wall layers by ultrasonography. In the five stenotic segments, angiography identified the cause of stenosis to be atherosclerosis in four patients and fibromuscular dysplasia in one patient. Ultrasound imaging, however, identified the disease process as atherosclerosis in three patients and as fibromuscular dysplasia in two patients. After renal angioplasty, ultrasonography identified three arterial dissections, only one of which was shown by angiography. CONCLUSIONS: These preliminary data indicate that catheter-based intravascular ultrasound imaging of the renal artery is feasible and correlates well with angiography in assessing renal artery size and also provides potentially important additional structural information that permits a better characterization of arterial pathology.

Aged↗
PubMed1991

Comparison of intravascular ultrasound, external ultrasound and digital angiography for evaluation of peripheral artery dimensions and morphology.

Validation of catheter-based intravascular ultrasound imaging has been based on comparisons with histology and digital angiography, each of which may have limitations in the assessment of arterial size and morphology. External, high-frequency ultrasound can accurately determine vessel dimensions and morphology and because, like ultravascular ultrasound, it also provides cross-sectional arterial ultrasound images, it may be a more appropriate technique for the in vivo comparison of arterial dimensions and morphology determined by intravascular ultrasound. Thus, intravascular ultrasound, external 2-dimensional ultrasound, Doppler color-flow imaging and digital angiography were compared for assessment of arterial dimensions and wall morphology at 29 femoral artery sites in 15 patients. Intravascular ultrasound and the other 3 imaging modalities correlated well in determination of lumen diameter (2-dimensional, r = 0.98, standard error of the estimate [SEE] = 0.14; Doppler color flow, r = 0.91, SEE = 1.11; angiography, r = 0.95, SEE = 0.91) and cross-sectional area (2-dimensional, r = 0.97, SEE = 0.04; Doppler color flow, r = 0.92, SEE = 0.14; angiography, r = 0.96, SEE = 0.08). However, lumen size measured by Doppler color flow was consistently smaller than that measured by the other 3 imaging modalities. Intravascular ultrasound detected arterial plaque at 15 sites, 5 of which were hypoechoic (soft) and 10 hyperechoic with distal shadowing (hard). Plaque was identified at 12 of 15 sites by Z-dimensional imaging (p = 0.30 vs intravascular ultrasound), but at only 6 of 15 sites by angiography (p = 0.003 vs intravascular ultrasound), only 1 of which was thought to be calcified plaque.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Surgical aortic valvuloplasty using the Cavitron Ultrasonic Surgical Aspirator: an invasive hemodynamic follow-up study.

Valve repair and calcium debridement in patients with calcific aortic stenosis, using the Cavitron Ultrasonic Surgical Aspirator (CUSA), results in a reduction in the aortic valve gradient while potentially avoiding long-term problems inherent to prosthetic valves. Invasive followup data in these patients has not previously been reported. Ten patients in whom CUSA debridement was performed underwent cardiac catheterization prior to and 8.0 +/- 2.5 months following the procedure. Compared to baseline, the aortic valve area significantly increased from 0.75 +/- 0.2 to 1.1 +/- 0.3 cm2 (p = 0.009) and the mean gradient was significantly reduced from 54 +/- 21 to 27 +/- 21 mmHg (p = 0.02) at followup. No significant change was noted in cardiac output, ejection fraction, left ventricular end systolic or diastolic volumes or left ventricular end diastolic pressure. However, 6 patients were found to have at least one grade worsening of aortic regurgitation. The development of increased aortic insufficiency in many patients after CUSA aortic valve debridement will likely limit this procedure's clinical utility.

Aged↗
PubMed1991

Rapid and accurate diagnosis of pulmonary emboli in a canine model using intravascular ultrasound imaging.

We utilized intravascular ultrasound (IVUS) imaging in a canine pulmonary embolism model to visualize experimental emboli. The images obtained were compared with those obtained by single-plane pulmonary arteriography in each of six animals. The vessel lumen appeared patent by both methods prior to injection of autologous clot. After thrombi were injected, the vessels were again imaged using both techniques. Intravascular ultrasound was 100 percent sensitive in detecting emboli, and visualization was always rapid. There were no complications. It appears that IVUS imaging is a sensitive method for documenting the presence of clot in a canine pulmonary embolism model.

Animals↗
PubMed1990

Early and late changes in left ventricular systolic performance after percutaneous aortic balloon valvuloplasty.

To evaluate early and late hemodynamics after aortic valvuloplasty, 17 patients underwent first-pass radionuclide angiocardiography with simultaneous high-fidelity micromanometer pressure before, 10 minutes after and 6 months after aortic valvuloplasty. Pressure-volume and stress data were assessed. Immediately after the procedure, no significant change was observed in heart rate, systemic blood pressure, cardiac output or aortic insufficiency (as measured by visual or quantitative aortography). The mean and peak transvalvular gradient decreased from 64 to 36 mm Hg (p less than 0.001) and 76 to 38 mm Hg (p less than 0.001), respectively. The mean aortic valve area increased from 0.5 to 0.8 cm2 (p less than 0.001). Using echocardiography, meridional end-systolic wall stress decreased from 81 to 63 x 10(3) dynes/cm2 (p less than 0.001). Left ventricular ejection fraction increased from 0.48 to 0.54 (p less than 0.01), end-diastolic volume decreased from 161 to 143 ml (p less than 0.001) and end-diastolic pressure decreased from 18 to 13 mm Hg (p less than 0.01). Left ventricular stroke work (the area of the pressure-volume loop) also decreased from 17.5 to 14.7 x 10(6) ergs (p less than 0.001). The loop shifted to the left and downward. At the 6-month study, the mean and peak aortic valve gradient increased from 36 to 56 mm Hg (p less than 0.001) and 38 to 61 mm Hg (p less than 0.001), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Thrombotic and cardiovascular complications related to nonionic contrast media during cardiac catheterization: analysis of 8,517 patients.

The incidence of major complications associated with nonionic contrast media has not been defined in a large study. Accordingly, cardiovascular complications, especially thrombotic events, were prospectively evaluated in 8,517 consecutive patients undergoing diagnostic cardiac catheterization with either iopamidol (n = 6,293) or iohexol (n = 2,224). Thrombotic events were defined as coronary embolus, coronary occlusion, transient ischemic attack or stroke occurring at the time of catheterization. Thrombotic events occurred in 15 patients (0.18%). Coronary thrombus or embolus occurred in 7 patients, a thromboembolus from the ventricular catheter occurred in 1 patients and transient ischemic attack or stroke occurred in 7 patients. Six of 15 patients with thrombotic events were premedicated with heparin. Thrombotic events were unusual in that they tended to occur in clusters within short time intervals. On 1 occasion, a thrombus was observed in the catheter tip before embolization. Other cardiovascular complications were similarly low with an incidence of ventricular tachycardia/fibrillation of 0.1%, profound bradycardia of 0.2% and prolonged angina of 0.3%. There were 2 deaths unrelated to thrombotic events. Although the clinical thrombotic events associated with nonionic contrast have an unusual temporal clustering and may result in major complications, the overall incidence (0.18%) of these thrombotic complications with nonionic contrast agents is quite similar to that reported with ionic contrast media.

Aged↗
PubMed1990

Changes in left ventricular systolic performance immediately after percutaneous aortic balloon valvuloplasty.

To evaluate the acute changes in left ventricular (LV) performance before and immediately after percutaneous aortic valvuloplasty, 25 patients underwent first-pass radionuclide angiocardiography for construction of pressure-volume loops. Simultaneously, high-fidelity micromanometric aortic and LV pressures were recorded. Echocardiographic wall thickness was used to define wall stress. After valvuloplasty, no acute changes were observed in the heart rate, aortic systolic pressure, cardiac output or degree of aortic insufficiency. Valvuloplasty decreased the peak aortic valve gradient from 73 to 40 mm Hg (p less than 0.001) and the mean gradient from 61 to 30 mm Hg (p less than 0.001); aortic valve area increased from 0.55 to 0.80 cm2 (p less than 0.001). Meridional end-systolic wall stress decreased from 83 to 55 X 10(3) dynes/cm2 (p less than 0.01). LV ejection fraction increased from 0.41 to 0.48 (p less than 0.01). LV end-diastolic volume decreased from 186 to 160 ml (p less than 0.001), end-systolic volume decreased from 115 to 87 ml (p less than 0.001) and end-diastolic pressure decreased from 22 to 17 mm Hg (p less than 0.01). LV stroke work decreased from 16.0 to 14.0 X 10(6) erg (p less than 0.001). No change was observed in peak positive LV dP/dt or the end-systolic pressure-volume ratio. This study documents variable and complex changes in the measures of cardiac function after aortic valvuloplasty. A decrease in the amount of LV outflow obstruction with maintenance of the cardiac output at a decreased level of LV filling occurs.

Aged↗
PubMed1990

Balloon angioplasty of coarctation of the aorta evaluated with intravascular ultrasound imaging.

Intravascular ultrasound images were employed to evaluate aortic coarctation before and after balloon angioplasty. Measurements obtained with use of an ultrasound imaging catheter correlated well with measurements made with digital aortography, both in the area of coarctation and in areas proximal and distal to it. The intravascular ultrasound images dramatically revealed dissection of the aortic wall and an intimal flap that was not appreciated on cineaortography or digital subtraction angiography. Intravascular ultrasound imaging may yield important morphologic information unavailable by other imaging techniques. Such information may allow more precise definition of the results of intravascular procedures and improve understanding of lesion characteristics predictive of a successful outcome.

Adult↗
PubMed1990

Failure of balloon aortic valvuloplasty to result in sustained clinical improvement in patients with depressed left ventricular function.

Although balloon aortic valvuloplasty usually results in acute hemodynamic improvement, recurrent symptoms often occur within several months. The current study was designed to determine whether clinical characteristics, including invasive hemodynamic parameters of left ventricular (LV) performance, are predictive of short-term patient outcome. Eighty-one consecutive patients were prospectively enrolled in the study protocol. High-fidelity dual sensor micromanometer catheters, digital ventriculography and aortography and Fick cardiac output were measured before and immediately after balloon aortic valvuloplasty. Stroke work was defined from pressure-volume loops. The acute hemodynamic results obtained in patients with overall improved symptoms were compared to those with recurrent symptoms at 3 months. Fifty-three patients (65%) were improved at 3-month evaluation (group 1), whereas 28 patients (35%) had either returned to symptoms at baseline (17), had undergone aortic valve replacement (3) or had cardiac death (8). Compared to patients with improved symptoms, patients with recurrent symptoms demonstrated a lower cardiac output, higher LV end-systolic volume, decreased LV ejection fraction, diminished LV stroke work and decreased LV peak positive dP/dt. The final aortic valve area and change in aortic valve area did not predict which patients would develop recurrent symptoms. Stepwise logistic regression revealed that LV ejection fraction was the only independent predictor of overall status at 3 months (p = 0.002). Eighty-four percent of patients with an ejection fraction greater than 45% were improved. In the group with an ejection fraction greater than 45%, less than half of the patients demonstrated improved symptoms at short-term followup. Parameters of LV performance can accurately predict short-term patient outcome after balloon aortic valvuloplasty.

Aged↗
PubMed1990

A rapid, effective technique for retrograde crossing of valvular aortic stenosis using standard coronary catheters.

Retrograde crossing of valvular aortic stenosis can be challenging even to experienced angiographers. In 446 of 447 consecutive patients with aortic stenosis catheterized during the past 3 years, a technique using a standard Judkins right coronary catheter and a floppy straight tipped guide wire was successful in rapidly and efficiently crossing these pathologically distorted valves in retrograde fashion. Once the valve was crossed, the coronary catheter was replaced with a pigtail catheter for pressure and ventriculography. The majority of these valves required less than 2 min to cross using this technique. This method is valuable in limiting the time required for catheterization, thus helping to reduce procedure related morbidity in these oftimes critically ill patients.

Aged↗